AUTOMATED DRILLING-FLUID ADDITIVE SYSTEM AND METHOD

Abstract

An automated drilling-fluid additive system and method for on-site real-time analysis and additive treatment of drilling fluid to be injected into a well. The drilling fluid includes returned drilling fluid intended to be re-used, which has a variety of viscosity and other qualities resulting from its various preceding use. The target drilling fluid will have a variety of viscosity and other qualities depending upon and changing with various phases of drilling operations and various conditions encountered. The drilling fluid is analyzed in real time as it flows into the automated drilling-fluid additive system, and various additives are added to and thoroughly blended with the drilling fluid as needed to achieve the desired result. The blended drilling fluid is discharged from the automated drilling-fluid additive system in the proper condition for injection into a well.

Claims

1. An automated drilling-fluid additive system for on-site real-time analysis and additive treatment of drilling fluid to be injected into a well, comprising: (i) an upstream end having an inlet fluidly connected to the well; (ii) a chemical-addition unit adapted for safety and sturdiness appropriate to oilfield use, said chemical-addition unit being in fluid communication with the upstream end; (iii) at least one tote interchangeably mounted near said chemical-addition unit; (iv) a tote fluid line corresponding to each said tote, adapted to convey additive fluid into said chemical-addition unit; (v) an inline diagnostic unit mounted in said chemical-addition unit adapted to take measurements of flowing drilling fluid in real time; (vi) a controller adapted to analyze data received from said inline diagnostic unit via a diagnostic-unit connector, and to control the addition of additives based on such analysis; (vii) a flow-control valve corresponding to each said tote fluid line and injection line adapted to control the flow of an additive from each said tote through each said injection line according to control signals generated by said controller and communicated over a control line; (viii) a blending unit operationally connected to said chemical-addition unit having an outlet end adapted for delivery of blended drilling fluid to the well at a location upstream from said upstream end; and (ix) a controller communication unit upon said controller adapted to report operational data to, and receive instructions from, a remote communication unit.

2-4. (canceled)

5. The automated drilling-fluid additive system of claim 1, comprising an intake pump operationally connected to the inlet, where said intake pump further comprises being adapted to provide 150 psi.

6. The automated drilling-fluid additive system of claim 1, comprising an intake pump operationally connected to the inlet, where said intake pump further comprises being adapted to sense back pressure and lower the applied pressure in response.

7. The automated drilling-fluid additive system of claim 1, comprising an intake pump operationally connected to the inlet, where said intake pump further comprises being adapted to provide additional pressure sufficient to supply an increased flow of blended drilling fluid at said outlet end.

8. The automated drilling-fluid additive system of claim 1, where said blending unit further comprises an expanding additive area, which expands to at least twice the area at said inlet.

9. The automated drilling-fluid additive system of claim 1, where said blending unit further comprises an expanding additive area, which expands to at least 3 times the area at said inlet.

10. (canceled)

11. An automated drilling-fluid additive method for on-site real-time analysis and additive treatment of drilling fluid to be injected into a well, comprising: (i) providing an automated drilling-fluid additive system, comprising: (a) an upstream end having an inlet fluidly connected to the well; (b) a chemical-addition unit adapted for safety and sturdiness appropriate to oilfield use, said chemical-addition unit being in fluid communication with the upstream end; (c) at least one tote interchangeably mounted near said chemical-addition unit; (d) a tote fluid line corresponding to each said tote, adapted to convey additive fluid into said chemical-addition unit; (e) an inline diagnostic unit mounted in said chemical-addition unit adapted to take measurements of flowing drilling fluid in real time; (f) a controller adapted to analyze data received from said inline diagnostic unit via a diagnostic-unit connector, and to control the addition of additives based on such analysis; (g) a flow-control valve corresponding to each said tote fluid line and injection line adapted to control the flow of an additive from each said tote through each said injection line according to control signals generated by said controller and communicated over a control line; (h) a controller communication unit upon said controller adapted to report operational data to, and receive instructions from, a remote communication unit; and (i) a blending unit operationally connected to said chemical-addition unit having an outlet end adapted for delivery of blended drilling fluid to the well at a location upstream from said upstream end; (ii) providing said automated drilling-fluid additive system with said totes containing additives; (iii) providing said controller with instructions for a target composition of drilling fluid through said controller communication unit; (iv) monitoring operations through said controller communication unit; and (v) providing blended drilling fluid from said outlet for injection into the well.

12. (canceled)

13. The automated drilling-fluid additive system of claim 1, further comprising a mixing tank adapted for receiving drilling fluid and separate injection lines from said chemical-addition unit, and mixing and discharging mixed drilling fluid for injection.

14. The automated drilling-fluid additive system of claim 1, where said at least one tote further comprises at least three totes.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Reference will now be made to the drawings, wherein like parts are designated by like numerals, and wherein:

[0017] FIG. 1 is a schematic diagram of an embodiment of the automated drilling-fluid additive system and method of the invention in use;

[0018] FIG. 2 is a schematic diagram of another embodiment of the automated drilling-fluid additive system and method of the invention in use; and

[0019] FIG. 3 is a perspective view of the chemical-addition unit of the automated drilling-fluid additive system of the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0020] Referring to FIG. 1, the automated drilling-fluid additive system and method 10 is shown schematically, in use in coiled-tubing drilling operations with varying mixtures of fresh and returned drilling fluid blended with desired additives provided to a high-pressure injection pump for injection into the well.

[0021] In the embodiment shown in FIG. 1, the automated drilling-fluid additive system and method 10 provides a blending unit 40 enclosing blending components as treated below, and a chemical-addition unit 50 as treated below. This embodiment is meant to be used with a holding tank 41, in circumstances where a holding tank is used instead of providing blended drilling fluid directly to the coiled-tubing operation. The holding tank 41 can also be a mixing tank, if the blended drilling fluid needs additional mixing while being held in order to, for example, prevent settling or separating of additives.

[0022] In the embodiment shown in FIG. 2, the automated drilling-fluid additive system and method 10 provides a chemical-addition unit 50 which directly and separately supplies a mixing tank 42 with drilling fluid and the proper amount of each additive, to be blended in the mixing tank 42 before being supplied to the coiled-tubing operation. The drilling fluid blended with additives in the mixing tank 42 can optionally be either supplied directly to the coiled-tubing operation or can be held in a holding tank.

[0023] Referring to FIG. 3, the chemical-addition unit 50 provides an inline diagnostic unit 3 which takes real-time measurements of the flowing drilling fluid. The inline diagnostic unit 3 is mounted in the flow of drilling fluid in standard ways such as the 4-inch flanges shown. The inline diagnostic unit 3 further provides several sensors housed in a sensor housing 52. The chemical-addition unit 50 provides multiple peristaltic pumps 53 for delivery of additives through separate cam-lock hose connectors 54, with each peristaltic pump 53 having an input and output pair. The chemical-addition unit 50 provides a controller 21, treated below, having a controller display 51 such as a touch screen monitor for displaying data and for taking user input. The chemical-addition unit 50 provides a controller communication unit 25, treated below. The chemical-addition unit 50 also provides a frame for housing its components in a safe and sturdy manner appropriate to oilfield use.

[0024] Referring back to FIG. 1, standard totes 31, each containing an additive, are placed on or near the chemical-addition unit 50 and are connected to the structure by tote fluid lines 32. Each tote can be connected or disconnected for the purpose of replacing an empty tote or connecting totes with a different additive as needed for different phases of operations or different downhole conditions encountered.

[0025] In use, drilling fluid is drawn from an inlet 1 at an upstream end, through an intake pump 2, into the chemical-addition unit 50, to the blending unit 40, and through an outlet 9 at a downstream end. A conveyor pipe 5 runs through the blending unit 40 and provides a flow path for the drilling fluid. In a preferred embodiment the conveyor pipe 5 is bent to allow a long run of pipe within the blending unit 40. The diameter of the conveyor pipe 5 varies, as treated below, but is on average larger than the diameter of the pipes attached at the inlet 1 and outlet 9, and is at no point smaller.

[0026] Drilling fluid is pushed, by the intake pump 2, through the inline diagnostic unit 3 of the chemical-addition unit 50, and into the blending unit 40, through a conveyor pipe 5 and toward the outlet 9. A moderate pressure of approximately 150 psi is appropriate. If the high-pressure injection pump slows enough to place back pressure on the intake pump 2, the intake pump should lessen or stop the flow of drilling fluid through the conveyor pipe 5. In an embodiment, the pressure imparted by the intake pump 2 can be significantly increased in order to meet a high demand for blended drilling fluid at the high-pressure injection pump.

[0027] The incoming drilling fluid passes through an inline diagnostic unit 3 which takes real-time measurements of the flowing drilling fluid, from which measurements the viscosity and other qualities of the incoming drilling fluid can be determined. The instantaneous pressure and rate of flow of incoming drilling fluid is also measured. These measurements are conveyed to a controller 21 via a diagnostic-unit connector 22.

[0028] The controller 21 receives and processes instructions through a controller communication unit 25 which communicates with a remote communication unit 26. In a preferred embodiment, the communication is local-area wireless, for communications on-site in locations possibly remote from wireless telephone signals, plus wide-area or telephone wireless for use when a signal is available. The controller 21 can also provide data and status conditions to the remote communication unit 26. Based upon the received instructions for the desired qualities of a resulting blended drilling fluid, the controller 21 processes the data provided by the inline diagnostic unit 3 and determines what additives in what amount need to be added to the incoming drilling fluid, and what rate of flow of additives is appropriate to the instantaneous pressure and rate of flow of incoming drilling fluid.

[0029] The incoming drilling fluid then flows into an expanding additive area 3 of the conveyor pipe 5 which has a larger cross-sectional area which creates a pressure drop in the flow of drilling fluid. Injection lines 33 corresponding to the tote fluid lines 32 are provided in the expanding additive area 3. The additives in the totes 31 can flow into the lower-pressure expanding additive area 3 without having to overcome the resisting pressure existing elsewhere in the conveyor pipe 5.

[0030] The flow of additives from the totes 31 through the tote fluid lines 32 and injection lines 33 into the expanding additive area 3 is controlled by flow-control valves 24 which are in turn controlled by the controller 21 through control lines 23.

[0031] At this point, the additives are not likely to be well blended or mixed with the incoming drilling fluid. The poorly blended mixture then flows into a blending area 6 of the conveyor pipe 5. The blending area 6 has an even larger cross-sectional area which creates another pressure drop. The blending area 6 is provided with turbulence vanes 7 which interrupt any laminar flow and promote turbulent flow which mixes and blends the additives and the drilling fluid.

[0032] The now well blended drilling fluid then flows into a collimator area 8 which creates a laminar flow in the blended drilling fluid by passing portions of the fluid through long smaller tubes or passageways. A “gattling gun” type of tube arrangement is appropriate. Taking care not to reintroduce turbulence, the cross-sectional diameter of the conveyor pipe 5 is reduced to that of the outlet 9 and the pipe connected to the outlet for direct delivery of a laminar flow of blended drilling fluid to the high pressure pump which injects the blended drilling fluid into the well.

[0033] Because the blended drilling fluid discharged from the outlet 9 is completely blended and is in laminar flow without turbulence, no further processing or handling of the outflow, and no further blending or settling of turbulence in a holding tank is necessary, and would instead be detrimental. The blended drilling fluid is provided to the high-pressure injection pump in a laminar flow at a steady moderate pressure.

[0034] In the embodiment of FIG. 1, the blended drilling fluid flows from the outlet 9 into a holding tank 41, for later use by the coiled-tubing operation.

[0035] Referring to FIG. 2, in the illustrated embodiment drilling fluid and the separate additives at the proper determined flow rate are conveyed separately from the chemical addition unit 50 to a mixing tank 42, for mixing, and then to downstream end of the coiled-tubing operation.

[0036] Many other changes and modifications can be made in the system and method of the present invention without departing from the spirit thereof. I therefore pray that my rights to the present invention be limited only by the scope of the appended claims.