Process For the Reduction of Flaring/Venting Gases During Completions Operations

Abstract

A process for the reduction of flaring/venting gases during completions operations on an oil/gas well, said process comprising providing a well in need of completion; providing a system to capture oil and gas generated by the well; the system including a primary separator to separate an incoming well stream into a plurality of streams wherein a first stream is sent to a pipeline and a second stream is sent for further processing. The process further includes flowing and collecting a third stream of gas in a gas pressure vessel; compressing the collected gas in the vessel until parameters of compressed gas are compressed to provide a constant feed to the pipeline; and transferring the compressed gas to the gas pipeline wherein the process reduces the amount of gas flared and/or vented during operation by over 80%.

Claims

1. A process for the reduction of flaring/venting gases during completions operations on an oil/gas well, said process comprising the steps of: providing a well in need of completion; providing a system to capture oil and gas generated by said well; wherein said system comprises: a primary separator adapted to separate the incoming well stream into: a first stream of pipeline-worthy gas; a second stream of fluids; a third stream of gas which is collected; and a fourth stream of oil condensate which is collected; wherein said first stream of pipeline-worthy gas is sent to a pipeline and said second stream is sent for further processing; a low pressure stage separator adapted to remove water and sand from said second stream of fluids and generating a fifth stream of oil condensate which is collected; a low stage condensate separator wherein said fourth stream of oil condensate and said fifth stream of oil condensate are collected, said low stage condensate separator generating a sixth stream of gas which is collected; a compression unit; flowing said third stream of gas and sixth stream of gas to a gas pressure vessel; collecting said third stream of gas and sixth stream of gas into said gas pressure vessel; performing compression of said collected gas in said gas pressure vessel until parameters of compressed gas are such that it can be compressed by said compression unit providing a constant feed to said pipeline; and transferring said compressed gas to said gas pipeline; wherein said process reduces the amount of gas flared and/or vented during a completions operation by over 80%.

2. The process according to claim 1, wherein said compression is carried out using a compressor comprising a built-in system to monitor the pressure of the solution gas.

3. The process according to claim 1, further comprising a flare stack only for use in an emergency case.

4. The process according to claim 1, wherein said process reduces the amount of gas flared and/or vented during completions operations by over 90%.

5. The process according to claim 1, wherein said process reduces the amount of gas flared and/or vented during completions operations by over 95%.

6. The process according to claim 1, wherein said process reduces the amount of gas flared and/or vented during completions operations by over 97.5%.

7. The process according to claim 1, wherein said compression is carried out in 2 stages, a first stage using two separate reciprocating compressor systems to pressurize the solution gas from approximately 40 psi (275.8 kPa) to approximately 400 psi (2,757.9 kPa) at a flow rate of 15.4 e.sup.3 m.sup.3/day, and flowing the resulting fluid to a second compression stage.

8. The process according to claim 7, wherein said second stage of compression using a single reciprocating compressor system which can pressurize the solution gas from approximately 400 psi to approximately 700 psi to 800 psi at a flow rate of 15.0 e.sup.3 m.sup.3/day.

9. The process according to claim 7, wherein said compression is carried a compressor system which is designed to handle a two-phase flow (liquids and gases).

10. The process according to claim 1, wherein said system to capture oil and gas further comprises a metering unit adapted to measure the volume of at least one of said first, second, third, fourth, fifth, and sixth stream.

11. A process for the reduction of flaring/venting gases during completions operations on an oil/gas well, said process comprising the steps of: providing a well in need of completion; providing a system to capture oil and gas generated by said well; wherein said system comprises: a primary separator adapted to separate an incoming well stream into: a first stream of pipeline-worthy gas; a second stream of fluids; a third stream of gas which is collected; and a fourth stream of oil condensate which is collected; wherein said first stream of pipeline-worthy gas is sent to a pipeline and said second stream is sent for further processing; a compression unit; flowing said third stream of gas to a gas pressure vessel; collecting said third stream of gas into said gas pressure vessel; performing compression of said collected gas in said gas pressure vessel until parameters of compressed gas are such that it can be compressed by said compression unit to provide a constant feed to said pipeline; and transferring said compressed gas to said gas pipeline; wherein said process reduces the amount of gas flared and/or vented during a completions operation by over 80%.

12. The process according to claim 11, wherein said system further comprises a low pressure stage separator adapted to remove water and sand from said second stream of fluids and generating a fifth stream of oil condensate which is collected.

13. The process according to claim 11, wherein said system further comprises a low stage condensate separator wherein said fourth stream of oil condensate and said fifth stream of oil condensate are collected, said low stage condensate separator generating a sixth stream of gas which is collected.

14. The process according to claim 13, wherein said sixth stream of gas which is collected is sent to the gas pressure vessel.

15. The process according to claim 11, wherein said process reduces the amount of gas flared and/or vented during completions operations by over 90%.

16. The process according to claim 11, wherein said process reduces the amount of gas flared and/or vented during completions operations by over 95%.

17. The process according to claim 11, wherein said process reduces the amount of gas flared and/or vented during completions operations by over 97.5%.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0070] Features and advantages of embodiments of the present application will become apparent from the following detailed description and the appended figures, in which:

[0071] FIG. 1 illustrates a simplified process flow diagram for flowback operations according to a preferred embodiment of the present invention using pressurized storage and compression;

[0072] FIG. 2 shows a process flow diagram according to a preferred embodiment of the present invention;

[0073] FIG. 3 is a first phase PFD with fluid flow from the wellhead to the separator units according to a preferred embodiment of the process of the present invention;

[0074] FIG. 4 illustrates a simplified process flow diagram for the primary separator flow according to a preferred embodiment of the present invention;

[0075] FIG. 5 illustrates a simplified process flow diagram for the secondary separator flow according to a preferred embodiment of the present invention;

[0076] FIG. 6 illustrates a simplified process flow diagram for the gas pressure vessel flow according to a preferred embodiment of the present invention;

[0077] FIG. 7 illustrates a simplified process flow diagram for the bypass skid flow according to a preferred embodiment of the present invention;

[0078] FIG. 8a illustrates a simplified process flow diagram for the stage 1 compression flow according to a preferred embodiment of the present invention; and

[0079] FIG. 8b illustrates a simplified process flow diagram for the stage 2 compression flow according to a preferred embodiment of the present invention.

[0080] FIG. 9 shows the process flow diagram for flowback operations using venting from 400 bbl tanks;

[0081] FIG. 10 shows the process flow diagram for flowback operations using flaring; and

[0082] FIG. 11 illustrates a simplified process flow diagram for flowback operations according to a preferred embodiment of the present invention.

DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

[0083] Illustrated in FIG. 1 is a Process Flow Diagram (PFD). The simplified process flow diagram is broken down into stages to provide a high-level process explanation.

[0084] In referring to FIG. 1, in a first phase (130) of the process, high velocity well fluids (101) are produced from the well (110) and flowed to a primary separator (103). The primary separator separates the pipeline-worthy gas into a stream (105) and sends it to the pipeline (120). A stream of solution gas (111) can be extracted from the primary separator (103) and sent to phase 4 (190) to a compressor (192). A stream of condensate (109) can be extracted from the primary separator (103) and sent to phase 2 (150). The remaining fluids stream (107) are sent to phase 2 (150). According to a preferred embodiment of the present invention, the primary separator is still connected to the flare stack (160) in the case of emergency well upset or similar emergency.

[0085] According to a preferred embodiment of the present invention, there is a bypass skid (not shown in FIG. 1) present before the compression system. In times of well upset or emergency the bypass skid will automatically switch the flow to the bypass line (pink line) which is the top line on the outlet.

[0086] As illustrated in FIG. 2, the second phase is where the remaining stream of fluids (107) undergo the final stage of separation at lower pressures. A stream of water and sand (207) is collected from the secondary (low stage) separator (113) and disposed of appropriately. The condensate (209) is collected to be sold. A stream of recovered solution gas (211) from the secondary (low stage) separator (113) which was further separated from the water sand fluid and condensate was flowed to the gas pressure vessel. The low stage separators (103 and 113) gas outlets are configured in series to collect the solution gas. According to a preferred embodiment of the present invention, this collection of solution gas allows recovery of sufficient quantities of gas at each step of the process (primary separator, water and sand separator, and the condensate separator) for subsequent compression and redirecting this recovered compressed solution gas to the pipeline (120).

[0087] The third phase is where the solution gas is collected and stored (221). As more solution gas is flowed into the gas storage vessel, the pressure in the vessel builds until pre-determined parameters are met, and then solution gas is transferred to the compressor system (215) providing a constant feed by passing through the bypass skid (213) which can re-direct the collected solution gas to the flare stack (160) in case of an emergency.

[0088] As better illustrated in FIGS. 8a and 8b, according to a preferred embodiment, the compressor system (215) is comprised of a first stage of compression (217) and a second stage of compression (219) and compresses the solution gas to pipeline pressure so it can be conserved, flowed to the pipeline, and sold. There is a built-in system to monitor the pressure of the solution gas. This is solely for the purpose of protecting the compressor and ensuring safety. The first stage of compression (217) comprises a pair of compressors (801′ and 801″) arranged in parallel, while the second stage of compression comprises a single compressor (803) adapted to increase the pressure of the collected solution gas to achieve a pipeline pressure.

[0089] According to a preferred embodiment, a flare stack (160) can be retained as part of the process design for purely safety reasons in the event of an emergency. The flare will be utilized in cases where the compressor could be overwhelmed, and pressure needs to be relieved. The solution gas in these cases will be flowed to the flare stack to be combusted in emergency situations.

[0090] FIGS. 9 and 10 illustrate the common approaches to the completions operations of venting the collected solution gas to the atmosphere (FIG. 9) and flaring the solution gas to the atmosphere (FIG. 10). While each process comprises a first stage of separation (901 and 1001) and a second stage of separation (903 and 1003) there is no collection of solution gas resulting from either stages in these processes as the resulting stream from the first separator which is not sent to the pipeline is further processes to facilitate the disposal of the solution gas (either by venting (905) or flaring 1005)).

[0091] In referring to FIG. 11, according to another preferred embodiment of the present invention, in a first phase (1130) of the process, high velocity well fluids (1101) are produced from the well (110) and flowed to a primary separator (1103). The primary separator (1103) separates the pipeline-worthy gas into a stream (1105) and sends it to the pipeline (1120). A stream of condensate (1111) can be extracted from the primary separator (1103) and sent to a secondary separator (1123) where the solution gas is extracted from the water and sand and further sent to phase 3 (1190) to a compressor (1192). The compressed gas (1194) coming out of the separator is sent to the pipeline (1120). According to a preferred embodiment of the present invention, the primary separator is still connected to the flare stack (160) in the case of emergency well upset or similar emergency.

Single Well Flare/Vent Gas Conservation Process Flow Diagram Breakdown

[0092] In the preferred embodiment illustrated in FIG. 3, well fluids (301) are flowed from the wellhead through the Emergency Shutdown (ESD)(303) and data headers (well fluid measurement tools)(305) to the dual stage choke manifold (307). The choke manifold (307) provides control of well flowback fluids or well treatment fluids. Well fluids are either flowed to the primary separator unit (V-101)(309) or the water sand low stage unit (V-102)(311) depending on the pressure of the well fluids. High pressure fluids are flowed to V-101 while low pressure fluids during initial well clean-up are flowed to V-102. Fluid flow direction to the primary separator (via V-101) and the secondary separator (via V-102) is determined by a two 3-inch ball valves at a tee downstream of the manifold.

[0093] In the preferred embodiment illustrated in FIG. 4, the well fluids (401) flow into the primary separator (403) single inlet port. The primary separator (403) allows for the separation of most of the sand and water from the well fluid and sends the sand and water fluid (411) to the low stage water and sand separator secondary separator. Fluid flow from the sand outlet and water outlet is controlled by the pressure vessel and also has a 3-inch ball valve on the flow line. The condensate is mostly separated from the well fluids and flowed (407) to the compressor. The water and condensate volume is measured using the 2-inch flowmeter. The natural gas (405) is separated out, the volume is measured by the ABB total flow meter and flowed to the sales header (pipeline). The sales header line also has a 3-inch check valve which ensures gas flow only happens in one direction and a 3-inch ball valve to control fluid flow. In case of well upset there is a flare line (409) and a pressure safety valve (PSV) line to release over pressurized gas to the flare stack.

[0094] In the preferred embodiment illustrated in FIG. 5, the low stage water and sand separator (501) (also referred to as the secondary separator) further separates the sand from the fluid and is pumped through the sand blowdown to the sand tanks through the sand load line (503) to be disposed of. Sand blowdown flow is controlled using 2 3-inch ball valves, with a pump point to pump water to move the solids along the flow line. The water is further separated ensuring as much as possible of the condensate and solution gas is removed from the fluid. The water is then measured by the 3-inch flowmeter and flowed and to the water tanks (C-Ring) to be disposed of properly. The solution gas is collected and flowed to a pressurized gas storage vessel (505). The vessels are set in series of each other with a bypass so gas can be flowed straight to the pressurized gas storage vessel or compressor bypass if needed. In case of well upset there is a PSV line to release over pressurized gas to a flare stack (see FIG. 7).

[0095] In the preferred embodiment illustrated in FIG. 6, the pressurized gas storage vessel (601) is a low stage unit for solution gas storage. The vessel collects the solution gas from the primary separator, the secondary separator as fluid flow (505) and sends such to the bypass skid (607) via flow line (605). The bypass skid (607) in turn, feeds into the compressor (see 711 in FIG. 7). This solution gas volume is measure using ABB total flow meter.

[0096] In the preferred embodiment illustrated in FIG. 7, the solution and waste gas condensate (605) is collected from the preceding separation stages vessel and is sent through the bypass skid flow (607) to then reach the compressor system (711). In the case of emergency (overpressurized gas or the like) the gas flow may be diverted at the bypass skid (607) to a flare stack (713) for a temporary relief of the system.

Case Study

[0097] Data was collected from ConocoPhillips Canada's A-013-L pad, which is a 9 well pad, and have completed a case study on the amount of GHG emissions were released due to the solution gas. Measuring the solution gas through ABB flowmeters present on each of the separator units, the solution gas that was flared was 570.482 e.sup.3 m.sup.3 (thousands of cubic meters). This volume was recorded from Jan. 6, 2021 to Mar. 29, 2021 and is shown in Table 1. Other key data taken from the pad were the total hours each well was flowed during flowback operations and the composition of the gas taken from gas samples on PAD A-013-L. Table 2 highlights the total hours flowed on each well and Table 3 highlights the gas composition.

[0098] Using the case study data two scenarios are performed to demonstrate the total estimated GHG emissions on PAD A-013-L assuming both venting and flaring operations. All GHG emissions calculations utilize the formulas from the Western Climate Initiative (WCI) Quantification Methods. This exercise is used to give an estimate and quantify GHG emissions using the two most prevalent methods of disposal for waste solution gas. These values are estimates given all the data for PAD A-013-L and are used to estimate possible emissions reductions utilizing the process according to a preferred embodiment of the present invention. It is important to note that gas compositions and volumes may vary in different flowback completions and is only used for the purpose of providing a visual to GHG emissions.

Scenario A: GHG Emissions from Venting Solution Gas

[0099] In Scenario A, the measured solution gas produced during flowback on PAD A-013-L is assumed to be vented out of 400 bbl tanks to atmosphere. Venting is the release of natural gas to the atmosphere. The solution gas is under large amounts of pressure and temperature in the formation but when exposed to atmospheric pressures and temperatures the gas is released from the solution to the atmosphere. FIG. 9 shows the basic process flow for venting procedures broken down into simplified components.

TABLE-US-00001 TABLE 1 Total volume of Gas flared from each separator on A-013-L PAD (Jan. 6-Mar. 29, 2021) Separators Unit Cumm. (e3m3) HS-29 3.89 LS-38 8.83 HS-37 25.24 LS-31 68.65 HS-11 3.98 LS-29 47.65 HS-35 1.46 LS-46 187.42 HS-08 23.60 LS-44 51.36 HS-07 22.72 LS-33 34.60 LS-59 50.42 LS-36 34.51 LS-54 4.31 LS-28 1.85 Total 570.48

TABLE-US-00002 TABLE 2 Flow time on PAD A-013-L PAD for each well between Jan. 6-Mar. 29, 2021 Total Flow time Time Flowed to Well Name (hours) Flare (hours) COP HZ Blueberry a-013-l/94-A-12 449.00 3.50 COP HZ Blueberry a-A13-l/94-A-12 1023.17 14.75 COP HZ Blueberry a-B13-l/94-A-12 481.33 4.17 COP HZ Blueberry a-C13-l/94-A-12 753.50 7.83 COP HZ Blueberry a-D13-l/94-A-12 1373.50 31.75 COP HZ Blueberry a-E13-l/94-A-12 431.75 1.75 COP HZ Blueberry a-F13-l/94-A-12 313.50 7.17 COP HZ Blueberry a-G13-l/94-A-12 901.42 119.50 COP HZ Blueberry a-H13-l/94-A-12 465.00 15.00 total 6192.17 205.42

TABLE-US-00003 TABLE #3 Gas Analysis taken from PAD A-013-L Component Mole Fraction H.sub.2 0.0000 He 0.0000 N.sub.2 0.0007 CO.sub.2 0.0009 H.sub.2S 0.0000 C.sub.1 0.6060 C.sub.2 0.2044 C.sub.3 0.1211 iC.sub.4 0.0185 C.sub.4 0.0304 iC.sub.5 0.0067 C.sub.5 0.0058 C.sub.6 0.0026 C.sub.7 0.0020 C.sub.8 0.0008 C.sub.9 0.0001 C.sub.10 0.0000 C.sub.11 0.0000 C.sub.12+ 0.0000 Total 1.0000

[0100] Using the case study data two scenarios are performed to demonstrate the total estimated GHG emissions on PAD A-013-L assuming both venting and flaring operations. All GHG emissions calculations utilize the formulas from the Western Climate Initiative (WCI) Quantification Methods. This is carried out to give an estimate and quantify GHG emissions using the two most prevalent methods of disposal for waste solution gas. These values are estimates given all the data for PAD A-013-L and are used to estimate possible emissions reductions utilizing the process according to a preferred embodiment of the present invention. It is important to note that gas compositions and volumes may vary in different flowback completions and is only used for the purpose of providing a visual to GHG emissions.

Scenario A: GHG Emissions from Venting Solution Gas

[0101] In Scenario A, the measured solution gas produced during flowback on PAD A-013-L is assumed to be vented out of 400 bbl tanks to atmosphere. Venting is the release of natural gas to the atmosphere. The solution gas is under large amounts of pressure and temperature in the formation but when exposed to atmospheric pressures and temperatures the gas is released from the solution to the atmosphere.

[0102] High velocity well fluids are produced from the well and flowed to the primary separator. The primary separator separates the pipeline worthy gas and sends it to the pipeline. The remaining fluids are sent to phase 2. The solution gas from the primary separator is collected in 400 bbl tanks.

[0103] The second phase is where the well fluids undergo the final stage of separation at lower pressures. The water and sand are collected from the low stage separator and disposed of appropriately. The condensate is collected in the low stage condensate separator, making sure any remaining water and sand is removed, then collected to be sold. The remaining solution gas is separated through the low stage separators and collected in the 400 bbl tanks.

[0104] The third phase is the venting of the solution gas out of the 400 bbl tanks to atmosphere releasing high concentrations of methane to the atmosphere.

Calculations for GHG Emissions if Solution Gas is Vented

[0105] Calculations were performed to demonstrate the GHG emission if the solution gas on PAD A-013-L is vented. The composition of the gas as highlighted in Table 3 is primarily CH.sub.4 which has a GWP 25 times greater than CO.sub.2. Calculations were utilizing equations taken from the WCI 2011 the volumetric emissions of CH.sub.4 and CO.sub.2 are calculated using Equation 360-27 below: [0106] (1) Estimate CH.sub.4 and CO.sub.2 emissions from natural gas emissions using Equation 360-27.

E.sub.s,i=E.sub.s,n.Math.M.sub.i  Equation 360-27 [0107] Where: [0108] E.sub.s,i=GHG i (CH.sub.4 or CO.sub.2) volumetric emissions at standard conditions. [0109] E.sub.s,n=Natural gas volumetric emissions at standard conditions. [0110] M.sub.i=Mole fraction of GHG i in the natural gas.

[0111] The volumetric emissions calculated using PAD A-013-L's data is 513 m.sup.3 for CO.sub.2 and 345,712 m.sup.3 for CH.sub.4. These volumetric values are then converted to mass emissions using Equation 360-28 (from WCI 2011) below. Table 4 highlights the volumetric emissions.

TABLE-US-00004 TABLE 4 Calculated Volumetric Data for CO2 and CH4 using equation 360-27 Where Component Value Units E.sub.s, n 570.482 e.sup.3m.sup.3 M.sub.CH4 0.6060 Mol. Frac. M.sub.CO2 0.0009 Mol. Frac. E.sub.S, CH4 345712.092 m.sup.3 E.sub.S, CO2 513.4338 m.sup.3 [0112] (s) GHG mass emissions. Calculate GHG mass emissions in carbon dioxide equivalent at standard conditions by converting the GHG volumetric emissions into mass emissions using Equation 360-28.

Mass.sub.s,i=E.sub.s,i×ρ.sub.i×GWP.sub.j×0.001  Equation 360-25

Where:

[0113] Mass.sub.s,i=GHG i (either CH.sub.4 or CO.sub.2) mass emissions at standard conditions (tonnes CO.sub.2e) [0114] E.sub.s,i=GHG i (either CH.sub.4 or CO.sub.2) volumetric emissions at standard conditions (m.sup.3) [0115] r.sub.i=Density of GHG i (1.86 lkg/m.sup.3 for CO.sub.2 and 0.678 kg/m.sup.3 for CH.sub.4 at STP of 15 degrees Celsius and 1 atmosphere) [0116] GWP=Global warming potential of GHG i (1 for CO.sub.2 and 25 for CH.sub.4) [0117] 0.001 Conversion factor from kilograms to tonnes.

TABLE-US-00005 TABLE 5 Calculated Mass Emissions Venting Operations Where component value Units E.sub.S, CH4 345712.092 m.sup.3 E.sub.S, CO2 513.4338 m.sup.3 GWP CH4 25 tonnes CO.sub.2-eq/tonne GWP CO2 1 tonnes CO.sub.2-eq/tonne ρ.sub.CH4 0.678 kg/m.sup.3 ρ.sub.CO2 1.861 kg/m.sup.3 Mass.sub.s, CH4 5859.819959 tonnes CO.sub.2-eq Mass.sub.s, CO2 0.955500302 tonnes CO.sub.2-eq Total CO.sub.2-eq 5860.77546 tonnes CO.sub.2-eq

[0118] The mass emissions calculated for CO.sub.2 are 0.96 tonnes CO.sub.2-eq and the mass emissions for CH.sub.4 is 5,860 tonnes CO.sub.2-eq, highlighted in Table 5. The total calculated mass emissions are the sum of the emissions from CO.sub.2 and CH.sub.4. The total calculated emissions for the 9 well PAD A-013-L during flowback operations is 5,861 tonnes CO.sub.2-eq.

Scenario B: GHG Emissions from Flaring Solution Gas

[0119] In Scenario B, the measured solution gas produced during flowback on PAD A-013-L is assumed to be sent to a flare stack and combusted. By combusting the solution gas, the methane is combusted into CO.sub.2 which reduces the GHG emissions. FIG. 10 shows the basic process for flaring operations during flowback operations.

[0120] High velocity well fluids are produced from the well and flowed to the primary separator. The primary separator separates the pipeline worthy gas and sends it to the pipeline. The remaining fluids are sent to phase 2. The solution gas is collected and flowed to the flare stack.

[0121] The second phase is where the well fluids undergo the final stage of separation at lower pressures. The water and sand are collected from the low stage separator and disposed of appropriately. The condensate is collected in the low stage condensate separator, making sure any remaining water and sand is removed, then collected to be sold. The remaining solution gas is separated through the low stage separators and flowed to the flare stack.

[0122] The third phase is the flaring of the solution gas at the flare stack. The solution gas is combusted which converts the CH.sub.4 to CO.sub.2 to reduce GHG emissions.

Calculations for GHG Emissions if Solution Gas is Flared

[0123] Because CH.sub.4 has a Global Warming Potential (GWP) 25 times greater than that of CO.sub.2, combusting the CH.sub.4 and converting it into CO.sub.2 reduces the GHG emissions. This is calculated using equations taken from the WCI 2011. The volumetric flared emissions are calculated using Equations 360-15, 360-16, 360-17, 360-18 reproduced below: [0124] (4) Calculate GHG volumetric emissions at actual conditions using Equations 360-15, 360-16, 360-17, and 360-18.

[00001]$\begin{array}{cc}E\text{?}=V\text{?}\times \left(1-\eta \right)\times X\text{?}& \mathrm{Equation}360-15\end{array}$$\begin{array}{cc}E\text{?}\left(\mathrm{noncombusted}\right)=V\text{?}\times X\text{?}& \mathrm{Equation}360-16\end{array}$$\begin{array}{cc}E\text{?}\left(\mathrm{combusted}\right)=.Math.\text{?}\eta \times V\text{?}\times Y\text{?}\times R\text{?}& \mathrm{Equation}360-17\end{array}$$\begin{array}{cc}E\text{?}\left(\mathrm{total}\right)=E\text{?}\left(\mathrm{combusted}\right)+E\text{?}\left(\mathrm{noncombusted}\right)& \mathrm{Equation}360-18\end{array}$$\text{?}\text{indicates text missing or illegible when filed}$

Where:

[0125] E.sub.a,CH4=Contribution of annual noncombusted CH.sub.4 emissions from flare stack under ambient conditions (m.sup.3). [0126] E.sub.a,CO2(non-combusted)=Contribution of annual CO.sub.2 emissions from CO.sub.2 in the inlet gas passing through the flare noncombusted under ambient conditions (m.sup.3). [0127] E.sub.a,CO2 (combusted)=Contribution of annual CO.sub.2 emissions from combustion from flare stack under ambient conditions (m.sup.3). [0128] V.sub.a=Volume of natural gas sent to flare during the year (m.sup.3). [0129] η=Percent of natural gas combusted by flare (default is 98 percent). For gas sent to an unlit flare, is zero. [0130] X.sub.i=Mole fraction of GHG i in gas to the flare. [0131] Y.sub.j=Mole fraction of natural gas hydrocarbon constituents j (i.e., methane, ethane, propane, butane, and pentanes plus) [0132] R.sub.j=Number of carbon atoms in the natural gas hydrocarbon constituent j (i.e., 1 for methane, 2 for ethane, 3 for propane, 4 for butane, and 5 for pentanes plus).

TABLE-US-00006 TABLE 6 Calculated Volumetric Emissions Flaring Operations Where component Value Units V 570.482 E3m3 η 0.98 X.sub.CH4 0.6060 Mol frac X.sub.CO2 0.0009 Mol frac E.sub.a, CH4 6914.24184 m.sup.3 E.sub.a, CO2 (noncombusted) 513.4338 m.sup.3 E.sub.a, CO2 (combusted) 935383.9655 m.sup.3 E.sub.a, CO2 (total) 935897.3993 m.sup.3

[0133] The volumetric emissions using for flaring operations using PAD A-013-L's data are calculated to be 935,897 m3 for CO2 and 6,914 m3 for CH.sub.4, highlighted in table 6. These volumetric values are then converted to mass emissions again using Equation 360-28.

TABLE-US-00007 TABLE 7 Calculated Mass Emissions Flaring Operations Where component value Units E.sub.S, CH4 6914.24184 m3 E.sub.S, CO2 935897.3993 m3 GWP CH.sub.4 25 tonnes CO.sub.2-eq/tonne GWP CO.sub.2 1 tonnes CO.sub.2-eq/tonne ρ.sub.CH4 0.678 kg/m.sup.3 ρ.sub.CO2 1.861 kg/m.sup.3 Mass.sub.s, CH4 1741.70506 tonnes CO.sub.2-eq Mass.sub.s, CO2 117.1963992 tonnes CO.sub.2-eq Total CO.sub.2-eq 1858.901459 tonnes CO.sub.2-eq

[0134] The mass emissions calculated for CO2 are 117 tonnes CO.sub.2-eq and the mass emissions for CH4 is 17,412 tonnes CO.sub.2-eq, highlighted in Table 7. The total calculated mass emissions are the sum of the emissions from CO2 and CH4. The total calculated emissions for the 9 well PAD A-013-L during flowback operations is 1,859 tonnes of CO.sub.2-eq.

Calculated GHG Emissions Reduction

[0135] Using PAD A-013-L as a case study, calculations were carried out in order to estimate the GHG emissions reduction possible utilizing a preferred embodiment of the process according to the present invention versus standard venting or flaring operations. In comparison to venting and flaring operations, the sources of GHG emissions come from the compressor system and the fuel consumption needed to run the system's power source during the compression process, in this case a natural gas driven engine. According to a preferred embodiment, the process seeks to eliminate all GHG emissions from flaring or venting solution gas.

[0136] The maximum fuel consumption rate is used to determine the total amount of fuel possibly needed during flowback operations. The maximum fuel consumption is 1,203 m.sup.3/day. This is converted to an hourly rate of 50.13 m.sup.3/hour, which is the fuel requirement of 100% load, which is conservative. The total hours where solution gas was flowed to flare on PAD A-013-L was recorded to be 205.42 hours as shown in Table 2. The total amount of fuel needed is then calculated by multiplying the fuel consumption per hour by the total hours flowed to flare and, is calculated to be 10,297 m.sup.3.

[0137] Compressor run equivalent to hours with volumes to flare at A-013-L is conservative because the gas storage for the process functions as an accumulator tank so that volumes can be reserved until a suitable amount of waste gas is available to enable efficient operation of the compressor. The compressor is automated to start based on sufficient waste gas volumes and rate (pressure) being available from gas storage and stop again when the pressure becomes too low, so the total number of hours the compressor will run will be less than the hours recorded at PAD A-013-L. The mass of CO.sub.2-eq can then be calculated using Equation 20-1 from the WCI 2011 as shown below: [0138] Calculation Methodology 1. Calculate the annual CO.sub.2 mass emissions for each type of fuel by substituting a fuel-specific default CO.sub.2 emission factor, a default high heat value, and the annual fuel consumption into Equation 20-1:

CO.sub.2=Fuel×HHV×EF×0.001  Equation 20-1

Where:

[0139] CO.sub.2= [0140] Fuel=Mass or volume of fuel combusted per year (express mass in tonnes for solid fuel, volume in standard cubic meters for gaseous fuel, or volume in kilolitres for liquid fuel). [0141] HHV=Default high heat value of the fuel, from Table 20-1 and 20-1a (GJ per tonne for solid fuel, GJ per kilolitre for liquid fuel, or GJ per cubic meter for gaseous fuel). [0142] EF=Fuel-specific default CO.sub.2 emission factor, from Tables 20-1a, 20-2, 20-3, 20-5, or 20-7, as applicable (kg CO.sub.2/GJ). [0143] (HEW×EF) instead of using separate HHV and EF values, you can replace the two values by using default emission factors from Tables 20-2, 20-3, or 20-5, as applicable (in units of kg CO.sub.2 per tonne for solid fuel, kg CO.sub.2 per kilolitre for liquid fuel, or kg CO.sub.2 per cubic meter for gaseous fuel) [0144] 0.001=Conversion factor from kilograms to tonnes.

TABLE-US-00008 TABLE 8 Calculated Mass Emissions from Compressor System Fuel Consumption Where component value Units HHV Natural Gas 0.03832 GJ/m.sup.3 Default CO2 emission Factor Nat Gas 56.13 kg CO.sub.2/GJ Max Compressor System estimated 1203 m.sup.3/day Fuel Consumption Total Fuel Consumption over life 10296.6775 m.sup.3 of A-13-L Mass.sub.s, CO2, A-13-L 22.14714011 tonnes CO.sub.2-eq

TABLE-US-00009 TABLE 9 Calculated Volumetric Emissions from Compressor System Where component value Units E.sub.S, CO2 22.375 Sm.sup.3/month E.sub.S, CH4 1.2416667 Sm.sup.3/month Count 1 Unit EF.sub.CO2 268.5 Sm.sup.3/year EF.sub.CH4 14.9 Sm.sup.3/year EF.sub.CO2 22.374 Sm.sup.3/month EF.sub.CH4 1.241666667 Sm.sup.3/month

TABLE-US-00010 TABLE 10 Total Calculated CO2-eq Emissions for compressor system Where component value Units E.sub.S, CO2 22.375 m3 E.sub.S, CH4 1.2416667 m3 GWP CH4 25 tonnes CO.sub.2-eq/tonne GWP CO2 1 tonnes CO.sub.2-eq/tonne ρ.sub.CH4 0.678 kg/m.sup.3 ρ.sub.CO2 1.861 kg/m.sup.3 Mass.sub.s, CH4 0.04163988 tonnes CO.sub.2-eq/month Mass.sub.s, CO2 0.02104625 tonnes CO.sub.2-eq/month Total CO.sub.2-eq 0.06268613 tonnes CO.sub.2-eq/month Total emissions for A-13-L 22.3351985 tonnes CO.sub.2-eq

[0145] The total emissions from fuel consumption are determined to be 22.15 tonnes CO.sub.2-eq. The Project utilizes a hydraulic compressor which does not have any operational venting procedures. A calculation was still completed to account for any possible emissions from the compressor during its operation in the case there were any minimal venting GHG emissions.

[0146] Equation 360-22 is used to calculate the emissions volumetric emissions for CH.sub.4 and CO.sub.2 by multiplying the one compressor by the corresponding emissions factors for CH.sub.4 and CO.sub.2 assuming standard conditions. The emission factor (EF) for CH.sub.4 is 268.5 Sm3/year and 14.9 Sm3/year for CO.sub.2 as described in the equation. The volumetric emissions are then converted to a mass in tonnes CO.sub.2 emitted using Equation 360-28. The calculated emissions are then scaled to the total months the compressor will be utilized during the flowback operations.

[0147] Onshore petroleum and natural gas production shall calculate emissions from well-site reciprocating compressors as follows using Equation 360-22:

E.sub.s,i=Count×EF.sub.i  Equation 360-22

Where:

[0148] E.sub.s,i=Annual total volumetric GHG emissions at standard conditions from reciprocating compressors (m.sup.3/year). [0149] Count=Total number of well-site reciprocating compressors for the reporter. [0150] EF.sub.i=Emission factor for GHG i (either CH.sub.4 or O.sub.2). Use 272.7 Sm.sup.3/year per compressor for CH.sub.4 and 15.2 Sm.sup.3/year per compressor for CO.sub.2 at 20° C. and 1 atmosphere or 268.5 Sm.sup.3/year per compressor for CH.sub.4 and 14.9 Sm.sup.3/year per compressor for CO.sub.2 at 15.6° C. and 1 atmosphere, or as adjusted for different temperatures.

[0151] Total Project emissions is the sum of emissions from fuel consumption and the emissions from the compressor and the calculated emissions during PAD A-013-L is 22.3 tonnes CO.sub.2-eq. By analysis it is easy to see that the emissions saved by implementing the process has huge benefits in terms of GHG emissions reductions. GHG emissions reductions are calculated by taking the traditional operations or base case and subtracting the emissions from the new process. This gives a tangible value of how much GHG emissions are being reduced by implementing the process. In comparison to venting operations, the GHG emissions reductions are 5,838 tonnes CO.sub.2-eq. In comparison to flaring operations, the GHG emissions reductions are 1,837 tonnes CO.sub.2-eq.

TABLE-US-00011 TABLE 11 Total emissions reductions for flaring and venting operations Where value Units component Tonnes CO.sub.2-eq Emissions reductions (venting) for A-13-L 5838.440261 Tonnes CO.sub.2-cq Emissions reductions (flaring) for A-13-L 1836.566261 Tonnes CO.sub.2-eq

Summary

[0152] It is important to understand current industry practices utilize both venting and flaring operations. As of right now there are now regulations that mandate flaring of solution gas in Alberta but in British Columbia there are regulations against venting solution gas. It is difficult to estimate what percent of wells utilize which operation, so a sensitivity analysis was performed to show the total possible emissions if either venting or flaring operations are used. Comparing venting to flaring, it is estimated venting produces more than 3-times as much carbon emissions as flaring procedures. Assuming venting operations are used on PAD A-013-L, the GHG emissions are calculated to be 5,861 tonnes CO.sub.2-eq. Assuming flaring operations are used on PAD A-013-L, the total calculated GHG emissions is 1,859 tonnes CO.sub.2-eq. This is also only considering operations for one 9 well pad over a 3-month period. Broken down per well by dividing the GHG emissions by the number of wells (in this case 9), one can get a general estimate for emissions per well for each operation. Venting operation on average calculated GHG emissions per well was 651.2 tonnes CO.sub.2-eq and flaring operations on average calculated GHG emissions per well was 206.5 tonnes of CO.sub.2-eq.

[0153] These values can be used to further scale estimated GHG emissions due to venting or flaring of solution gas during the flowback process. In 2019, 442 natural gas wells were drilled in Alberta and British Columbia that could have utilized the process according to a preferred embodiment of the present invention. In 2020, 132 natural gas wells were drilled in Alberta and British Colombia that could utilize the patent process (BOE Report 2021). Taking the wells drilled in 2019 and 2020 to provide a general estimate of emissions due to disposal of solution gas, it is evident that massive amounts of GHG emissions are being released. In 2019, assuming all wells used venting operations and all emissions from the wells are similar to the emissions from the wells on PAD A-013-L, the GHG emissions are estimated to be 287,829 tonnes CO.sub.2-eq. Similarly, the estimated emissions if all wells used flaring operations in 2019 is 91,292 tonnes CO.sub.2-eq. This exercise was completed for 2020 as well even though 2020 was heavily influenced by COVID-19 which had a direct effect on the number of wells drilled. In 2020 estimated venting operations GHG emissions are 85,958 tonnes CO.sub.2-eq and the estimated flaring operations GHG emissions are 27,264 tonnes CO.sub.2-eq.

TABLE-US-00012 TABLE 12 GHG emissions for flaring and venting operations of PAD A-103-L and Estimated for 2019 and 2020 Where value Units Scenario Tonnes CO.sub.2-eq Total venting GHG Emissions for 5860.77546 Tonnes CO.sub.2-eq A-13-L Total flaring GHG Emissions for 1858.901459 Tonnes CO.sub.2-eq A-13-L Venting GHG Emissions per well for 651.1972733 Tonnes CO.sub.2-eq A-13-L Flaring GHG Emissions per well for 206.5446066 Tonnes CO.sub.2-eq A-13-L Estimated venting GHG Emissions 287829.1948 Tonnes CO.sub.2-eq for 2019 Estimated flaring GHG Emissions 91292.7161 Tonnes CO.sub.2-eq for 2019 Estimated venting GHG Emissions 85958.04008 Tonnes CO.sub.2-eq for 2019 Estimated flaring GHG Emissions 27263.88807 Tonnes CO.sub.2-eq for 2019

[0154] Performing the sensitivity analysis provides an immediate need for steps need to be taken to provide a closed loop flowback process that captures more of the GHG emissions. The proposed compression process could revolutionize the completions industry by removing venting or flaring of solution gas during operations and essentially eliminating GHG emissions during the flowback process.

[0155] By breaking down the GHG emissions per well for the new process, it is estimated that per well on A-013-L, 2.48 tonnes of CO.sub.2-eq are produced. This is a significant decrease in CO.sub.2-eq in comparison to flaring or venting operations. Reductions were calculated for 2019 and 2020 for both venting and flaring operations shown in Table 13 below.

TABLE-US-00013 TABLE 13 GHG emissions reductions for flaring and venting operations of PAD A-103-L and Estimated for 2019 and 2020 Where value Units component Tonnes CO.sub.2-eq Total Emissions for A-13-L 22.33519848 Tonnes CO.sub.2-eq Estimated Emissions per well for 2.48168872 Tonnes CO.sub.2-eq A-13-L Estimated GHG Emissions reductions 286732.2884 Tonnes CO.sub.2-eq vs venting for 2019 Estimated GHG Emissions reductions 90195.80968 Tonnes CO.sub.2-eq vs flaring for 2019 Estimated GHG Emissions reductions 85630.45717 Tonnes CO.sub.2-eq vs venting for 2020 Estimated GHG Emissions reductions 26936.30515 Tonnes CO.sub.2-eq vs flaring for 2020

[0156] By assuming every well drilled utilizes flaring of solution gas during completions operations, in 2019, 90,196 tonnes of CO.sub.2-eq and in 2020, 26,936 tonnes of CO.sub.2-eq could have been conserved. This is assuming best case scenario where all well utilize flaring which is most certainly not the case. This highlights the benefit of implementation of the patent process.

Economic Analysis

[0157] An economic analysis was completed using the Case Study on PAD A-013-L. The cost is calculated using an estimated breakdown of all the required equipment and labour necessary to implement the process.

Total Estimated Cost for Patent Process Pilot Implementation

[0158] The equipment cost for the patent process pilot comprises:

[0159] Total Equipment Cost=$764,092.00

[0160] Equipment Cost Breakdown: Pressure Control and Bypass skid=$40,232.00 [0161] Storage Tank Components=$82,385.00 [0162] Compressor=$618,550.00 [0163] Supply Line System=$22,925.00

[0164] The labour costs are based on the costs of an operations team upon implementation of a preferred embodiment of the process according to the present invention. Site Specific Design/Engineering and Project Management allows for costs to implement the new equipment within an already functional flowback operations design ($15,000). Construction/installation allow for the new compressor and associated equipment to be installed and tied-into an already functional design ($40,000). Reporting allows for metering required to enable post-Project GHG reporting and verification ($10,000). Testing and Verification allows for the post-Project GHG reporting to be created and then validated by a third-party ($20,000). The total estimated cost is $849,092.

Total Estimated Savings for Patent Process Implementation

[0165] The largest form of cost savings is due to the carbon tax savings from utilizing the process according to a preferred embodiment of the present invention. Preferably, the process provides a significant reduction to GHG emissions. Currently, the British Columbian government has a $40/per tonne CO.sub.2-eq carbon tax, and the federal government has instated a $30/per tonne CO.sub.2-eq carbon tax. With both the provincial and federal tax to be increased yearly until 2022. PAD A-013-L was drilled in BC so the tax per tonne of CO.sub.2 emitted for the oil and gas producer is 70$/tonne CO.sub.2-eq.

[0166] This heavily incentivises oil and gas producers to significantly reduce their GHG emissions. PAD A-013-L used flaring operations and it is estimated that $128,600 could have been saved in carbon tax credit savings for the single pad. As of March 2021, Alberta natural gas prices are 2.54$CDN/GJ (Alberta Economic Dashboard 2021). The total value of the conserved natural gas that is uplifted to market gas quality is $18,316. In total between the savings in carbon tax credits and extra saleable gas, $146,916 could have been saved on PAD A-013-L by utilizing the process. Using the economics of PAD A-013-L, if the process was used for a full calendar year, the payback period for the compressor would be 1.65 years.

[0167] If all the drilled wells in 2019 utilized the process instead of venting during flowback, an estimated $20,148,044 could have been saved and in 2020 an estimated $6,017,063 could have been saved. Similarly, if all the drilled wells in 2019 utilized the process instead of flaring during flowback, an estimated $7,215,208 could have been saved and in 2020 an estimated $2,154,768 could have been saved. The process according to a preferred embodiment of the present invention has huge economic implications and savings which will only increase based on carbon tax acceleration. The federal government will set the carbon tax to $50/tonnes CO.sub.2-eq by 2022 with the possibility of increasing further. The economic viability will become even greater as the carbon tax increases and the need for closed loop flowback process will be mandatory for sustainable operations. Table 14 below highlights the potential savings vs venting or flaring.

TABLE-US-00014 TABLE 14 Estimated cost saving using the compressor system vs Flaring and Venting Operations on PAD A-013-L and Estimated for 2019 and 2020 Where Scenario Value Total savings for A-13-L if venting $410,254 Total savings for A-13-L if flaring $146,916 Estimated savings per well for A-13-L if venting $45,584 Estimated savings per well for A-13-L if flaring $16,324 Estimated savings vs venting 2019 $20,148,044 Estimated savings vs flaring 2019 $7,215,208 Estimated savings vs venting 2020 $6,017,063 Estimated savings vs flaring 2020 $2,154,768

[0168] According to a preferred embodiment of the present invention, the process comprising the use of pressurized vessel and adapted compressors allows for closed loop flowback completions operations which will eliminate routine flaring and venting. This has significant GHG emissions reduction potential as demonstrated in the measurements taken on PAD A-013-L in the case study. During the completions process 570.482 e3m3 of natural gas was flared during flowback. The calculated GHG emissions produced from the flowback operations were 1,859 tonnes of CO.sub.2-eq. If the patent process were implemented, it is estimated that majority of these emissions could have been reduced as the process would have only produced 22.3 tonnes of CO.sub.2-eq if used on PAD A-013-L instead of flaring the entire amount of gas (570.482 e.sup.3 m.sup.3). This would amount to 1,837 tonnes of CO.sub.2-eq conserved and a total savings in carbon tax credits and saleable gas of $146,916. Preferably, this process has the potential for massive reductions in GHG emissions as well as significant savings for oil and gas producers. The process according to a preferred embodiment of the present invention utilizes advanced measurement technologies, pressurized vessels, and proprietary compression systems to conserve waste solution gas to the pipeline instead of having them being vented or flared.

[0169] While the foregoing invention has been described in some detail for purposes of clarity and understanding, it will be appreciated by those skilled in the relevant arts, once they have been made familiar with this disclosure that various changes in form and detail can be made without departing from the true scope of the invention in the appended claims.