AUTONOMOUS BLOWOUT PREVENTER
20230057814 · 2023-02-23
Inventors
- Stylianos Papadimitriou (Houston, TX, US)
- WANDA PAPADIMITRIOU (HOUSTON, TX, US)
- JASON A. PAPADIMITRIOU (HOUSTON, TX, US)
- NICHOLAS A. PAPADIMITRIOU (HOUSTON, TX, US)
Cpc classification
E21B33/0355
FIXED CONSTRUCTIONS
International classification
E21B33/035
FIXED CONSTRUCTIONS
Abstract
A BOP system is provided with sensors distributed along a length of a subsea blowout preventer to monitor objects within a blowout preventer and measure critical parameters. A subsea computer is programmed to detect a speed and direction of an object within the BOP. The computer is programmed to detect movement of an object that is not produced by the drilling rig.
Claims
1. A monitoring system for a subsea BOP, said subsea BOP defining a bore through said subsea BOP, said subsea BOP comprising a ram, said subsea BOP being operable to receive a string of pipe movable through said bore, comprising: a computer operatively connected to control opening and closing of said ram; and a plurality of sensors being mounted to said subsea BOP, said computer being programmed to utilize said plurality of sensors to detect a direction and a speed of an object within said subsea BOP.
2. The monitoring system of claim 1, further comprising said object comprising said string of pipe, said computer being programmed to determine when it is possible for said ram to shear said string of pipe and when it is not possible to shear said string of pipe.
3. The monitoring system of claim 2, further comprising said computer being programmed to detect a blowout based on said direction and said speed of said string of pipe within said subsea BOP, said plurality of sensors comprising a plurality of groups of sensors where each group is axially spaced at different axial positions with respect to said bore of said subsea BOP, said computer being programmed to send a warning signal to a surface position about said blowout when said string of pipe is moving due to said blowout, said computer being programmed to operate said ram to cut said string of pipe when said computer determines that it is possible to shear said string of pipe and after either receiving a human instruction to cut said string of pipe or when no response is made to said warning signal.
4. The monitoring system of claim 1, further comprising said object is a tubular object and said computer being programmed to determine a wall thickness of said tubular object within said subsea BOP.
5. The monitoring system of claim 1, further comprising said plurality of sensors comprising an electromagnetic sensor, said object comprising a metallic object, and said electromagnetic sensor being responsive to said metallic object within said subsea BOP.
6. The monitoring system of claim 1, wherein said plurality of sensors provide a plurality of signals wherein said computer is operable for determining one or more of vibration, sound, frequency, a lateral location of pipe that is offset from a vertical centerline of said subsea BOP or a or proximity to a subsea BOP internal wall thickness, an angle of a pipe within said subsea BOP with respect to said vertical centerline of said subsea BOP, inductance, an electromagnetic field, capacitance, contactivity, current, deflection, weight, flow rate, impedance, internal pressure, external pressure, fluid volume, length, rate, accumulator pressure, pressure, resistance, temperature, voltage, drill pipe internal pressure, a temperature gradient between seawater and well fluids, compression or tension of a body wall of a string of pipe inside said subsea BOP, flow of fluid through the string of pipe, a change in a shear force to cut said string of pipe, pipe imperfections, hardness, dimensions, wear, stress concentration, RFID information, speed and position of a piston rod, a speed and position of a piston, or speed and position of a said ram, density, or a combination of the above.
7. The monitoring system of claim 1, further comprising a surface sensor positioned at a surface position, said computer being programmed to utilize said surface sensor at said surface position, said computer being programmed as a warning system for audibly providing an alert in natural language or a tactile alarm or comprise a smart device programmed to provide an alarm for said blowout.
8. The monitoring system of claim 1, further comprising said computer being programmed to distinguish between a downhole tool, drill pipe joint, drill pipe body pump, motor, drill bit, heavyweight drill pipe, wireline, debris or another unknown object.
9. The monitoring system of claim 1, said computer being programmed to classify said object in said bore as a downhole tool, tool joint, pump, motor, drill bit, heavyweight drill pipe, debris, drill pipe joint, drill pipe body section, or unknown object.
10. The monitoring system of claim 1 further comprising a rig sensor operable to determine an internal pressure of a pipe and said computer being programmed to adjust a calculation of force to cut said pipe based on said internal pressure.
11. The monitoring system of claim 1 wherein said plurality of sensors comprise a noncontact sensor.
12. A monitoring system for a subsea BOP defining a bore through said subsea BOP operable to receive a string of drill pipe, said BOP comprising a ram, said string of drill pipe comprising a plurality of drill pipe connectors and a plurality of pipe bodies between said drill pipe connectors, comprising: a computer a plurality of groups of sensors positioned at a plurality of different locations along an axis of a bore though said subsea BOP, said computer being programmed to utilize said plurality of groups of sensors to detect an object moving through said bore.
13. The monitoring system of claim 12, wherein said computer is programmed to determine a plurality of parameters from said plurality of groups of sensors comprising one or more of wall thickness, imperfections, hardness, dimensions, wear, rate of wear, stress concentration, weight, lateral location, angle, fatigue of vibration, sound, frequency, a lateral location of pipe that is offset from a vertical centerline of said subsea BOP or a or proximity to a subsea BOP internal wall thickness, an angle of a pipe within said subsea BOP with respect to said vertical centerline of said subsea BOP, inductance, an electromagnetic field, capacitance, contactivity, current, deflection, weight, flow rate, impedance, internal pressure, external pressure, fluid volume, length, rate, accumulator pressure, pressure, resistance, temperature, voltage, drill pipe internal pressure, a temperature gradient between seawater and well fluids, compression or tension of a body wall of a string of pipe inside said subsea BOP, flow of fluid through the string of pipe, a change in a shear force to cut said string of pipe, pipe imperfections, hardness, dimensions, wear, stress concentration, RFID information, speed and position of a piston rod, a speed and position of a piston, or speed and position of a said ram, density, or a combination of the above.
14. The monitoring system of claim 12, wherein said object comprises tool joints, said computer is programmed to monitor a time interval between said tool joints passing through said plurality of groups of sensors to provide a speed of said tool joints passing through said subsea BOP and also to determine a direction of said tool joints passing through said subsea BOP.
15. The monitoring system of claim 12, further comprising said computer being programmed to utilize said plurality of groups of sensors to classify said object in said bore.
16. The monitoring system of claim 12, further comprising said computer being programmed to utilize said plurality of groups of sensors to classify said object in said bore as a downhole tool, tool joint, pump, motor, drill bit, heavyweight drill pipe, debris, drill pipe joint, drill pipe body section, or unknown object.
17. The monitoring system of claim 16, further comprising said computer being programmed to utilize a classification of said object to determine whether said ram can cut said object.
18. The monitoring system of claim 13, further comprising said computer being programmed to keep track of a depth of said object.
19. The monitoring system of claim 13, further comprising said computer being programmed to utilize said plurality of groups of sensors and a design profile or signal analysis or RFID tags to classify said object.
20. The monitoring system of claim 13, further comprising said computer being programmed to detect when an associated surface drilling rig is not in control of a movement of said object moving through said subsea BOP.
21. The monitoring system of claim 13, further comprising sensors in said subsea BOP to detect RFID chips embedded in said string of drill pipe, said computer is programmed to use previous inspection data to determine an amount of force to cut a particular pipe in said string of drill pipe based on information stored in said RFID chips.
22. The monitoring system of claim 21 further comprising a database to which said RFID chips are connected, said database permitting entry of information and review of said information.
23. A monitoring system to detect when a drilling rig is not in control of movement of an object in a wellbore, comprising: a BOP; BOP sensors mounted to said BOP; rig sensors mounted in said drilling rig; and a computer being programmed to detect when said BOP sensors detect movement of said object that is not produced by said drilling rig.
24. The monitoring system of claim 23, wherein said BOP sensors comprise a plurality of groups of sensors positioned at a plurality of different locations axially along an axis of a bore though said BOP, said computer being programmed to utilize said plurality of groups of sensors to detect said object moving through said bore.
25. The monitoring system of claim 24, wherein said computer is programmed to determine a plurality of parameters from said plurality of groups of sensors comprising one or more of wall thickness, imperfections, hardness, dimensions, wear, rate of wear, stress concentration, weight, lateral location, angle, fatigue, vibration, sound, frequency, a lateral location of pipe that is offset from a vertical centerline of said BOP or a or proximity to a BOP internal wall thickness, an angle of a pipe within said BOP with respect to said vertical centerline of said BOP, inductance, an electromagnetic field, capacitance, contactivity, current, deflection, weight, flow rate, impedance, internal pressure, external pressure, fluid volume, length, rate, accumulator pressure, pressure, resistance, temperature, voltage, drill pipe internal pressure, a temperature gradient between seawater and well fluids, compression or tension of a body wall of a string of pipe inside said BOP, flow of fluid through the string of pipe, a change in a shear force to cut said string of pipe, pipe imperfections, hardness, dimensions, wear, stress concentration, RFID information, speed and position of a piston rod, a speed and position of a piston, or speed and position of a said ram, density, or a combination of the above.
26. The monitoring system of claim 23, wherein said object comprises tool joints, said computer is programmed to monitor a time interval between said tool joints passing through said BOP sensors to provide a speed of said tool joints passing through said BOP and also to determine a direction of said tool joints passing through said BOP.
27. The monitoring system of claim 23 further comprising said computer is programmed to determine a speed and direction of an object passing through said BOP sensors.
28. The monitoring system of claim 23, further comprising said computer being programmed to utilize said BOP sensors to classify said object in said BOP.
29. The monitoring system of claim 23, further comprising said computer being programmed to utilize said BOP sensors to classify said object in said BOP as a downhole tool, tool joint, pump, motor, drill bit, heavyweight drill pipe, debris, drill pipe joint, drill pipe body section, or unknown object.
30. The monitoring system of claim 23, further comprising said computer being programmed to utilize a classification of said object to determine whether a ram in said BOP can cut said object.
31. The monitoring system of claim 23, further comprising said computer being programmed to keep track of a depth of said object.
32. The monitoring system of claim 23, further comprising said computer being programmed to utilize said BOP sensors and a design profile or signal analysis or RFID tags on said object to classify said object.
33. The monitoring system of claim 23, further comprising said object comprising a string of pipe, RFID sensors in said BOP to detect RFID chips embedded in said string of pipe, said computer is programmed to use previous inspection data to determine an amount of force to cut a particular pipe in a string of pipe based on information stored in a RFID chip for said particular pipe.
34. The monitoring system of claim 33 further comprising a database to which said RFID chips are connected, said database permitting entry of information and review of said information.
35. The monitoring system of claim 23 wherein said BOP is a subsea BOP.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0050] For a further understanding of the nature and objects of the present invention, reference should be had to the following detailed description, taken in conjunction with the accompanying drawings, in which like elements may be given the same or analogous reference numbers and wherein:
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[0075] While the present invention will be described in connection with presently preferred embodiments, it will be understood that it is not intended to limit the invention to those embodiments. On the contrary, it is intended to cover all alternatives, modifications, and equivalents included within the spirit of the invention.
DETAILED DESCRIPTION OF THE PRESENT INVENTION
[0076] Referring now to the drawings and more particularly to
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Description of a Simple Subsea BOP Stack
[0079] Turning now to
[0080] The AutoBOP operation environment is dynamic as is its interaction with the other dynamic machines. The operation environment Problem and the interaction Problem(s) never have a complete description and cannot be thoroughly predicted while they evolve or at the design phase or prior to deployment. Therefore, AutoBOP 4, through software of computer or predictive-controller 20, monitors and stores a sufficient number of parameters to represent the instantaneous real world Problems along with changes and trends in sufficient detail to solve the Problems it encounters. It should be understood that the solution(s) to the Problem(s) would most likely be dynamic, reacting to the environment and interaction changes that redefine the target. Only the target is well defined as the “delivery of successful results”, or stated differently, the sealing of the well to stop the uncontrolled flow of the formation hydrocarbons. Therefore, AutoBOP needs to function on its own in its environment as a stand-alone system.
[0081] Subsea AutoBOP 4 may comprise a number of annular preventers 4C, rams 4A and 4B and accumulator systems 10A, 10B, and 10C. The BOP “Class” is the total number of annular preventers (designated as “A”) and rams (designated as “R”), such as, Class 6-A2-R4. API S53 specifies the minimum subsea stack as a Class 5 comprising, at minimum, one annular, two pipe rams and two shear rams. For clarification, it should be noted that it is customary to describe BOP 4 from the bottom upwards and will be described accordingly herein. The
[0082] Accumulator systems 10A, 10B, 10C provide the hydraulic power to operate BOP 4, more specifically annular preventers 4C and shear ram 4B and pipe ram 4A. Accumulator system 10C further comprises pressure intensifier 12C, accumulator 11, and valves 13C, 12C, and 15C. Accumulator 11C is precharged at the surface, typically with nitrogen, to 3,000 psi at 20° C. for example. Accumulator 11C is then charged by the subsea hydraulic supply with sufficient volume of fluid to operate annular preventers 4C and rams 4A and 4B. The “Drawdown Test” (API S53 6.5.6.2) verifies that accumulator 11C is able to provide sufficient fluid volume and pressure to secure the well with final accumulator pressure of, at least, 200 psi above precharge pressure.
[0083] Valves 13C, 14C and 15C are controlled by computer 20 through peripheral-bus 21. Computer 20 may open or close valves 13C, 14C and 15C, either fully or partially. Computer 20 additionally monitors pistons 5 and the accumulator systems 10 via peripheral-bus 21. In other embodiments, accumulator system 10C may comprise a plurality of accumulator 11C, pressure intensifier 12C, valves 13C, 14C, 15C and similar components. It should further be understood that accumulator systems 10 comprise similar components as further illustrated in
[0084] A plurality of non-contact sensors 30 (See
[0085] Sensor interface 27 processes the analog signals from sensor 30 and converts said analog signals to a digital format under the control of computer 20. Computer 20 further provides controlled excitation 26 to sensors 30. AutoBOP both stores and transmits through communication link 22 the Problems and solutions for real-time interaction with the rig crew and further examination at a later time. It should be noted that the stored data would advance the knowledge of the designer and the operator. Furthermore, AutoBOP allows for external BOP control through the power and communication subsea connector 23. Computer 20 takes into account all other monitored parameters through data acquisition system 24 and data acquisition sensors 25 to include with the real-time data.
[0086] A drill string is a dynamic machine that interacts with AutoBOP 40 and comprises a number of drill pipe joints 7, lengthwise sufficient, to form a slender-column that is elastically unstable. One may push (placed under compression) one drill pipe joint without the drill pipe joint deforming; a behavior consistent with that of a short-column where the material strength is in control. However, as the length of the drill string increases, the end-conditions, its modulus of elasticity and slenderness become the controlling factors, not its strength. Elastic instability will result in the deformation of a 10,000′ drill string when it is pushed upwards by the formation hydrocarbons 9 as illustrated in
[0087] The direction of the loads the drill string endures and its behavior under loading define its interaction with BOP 4 and therefore the BOP missions. Another objective of the present invention is to teach how to automatically detect and recognize the drill pipe 7 behavior inside BOP 4 annulus 8, said behavior also been an indication of a well kick, and to formulate a plan to bring the well under control early enough while control is still possible.
[0088] An additional benefit of the present invention is that the detection and recognition of drill pipe 7 behaviors inside annulus 8 during operations may prevent damage to drill pipe, BOP 4, the rubber goods and similar items during drilling.
[0089] Prior art BOPs are designed to function in a static, designer-specified environment, not in a real-world environment; the root-cause of the BOP failures. When the designer defines the BOP environment, the designer defines an event-space static convenient condition. For example, the BOPs today are designed to shear drill pipe nominal body-wall that is static, under tension and near the center of the shear rams without any feedback if any of the assumptions are valid (see
[0101] The Deepwater Horizon BOP functioned as-designed and successfully completed an EDS in June of 2003 under the above controlled conditions proving that the Deepwater Horizon BOP was maintained properly all along. This, however, is assumed erroneously to be adequate proof that BOP 4 could also arrest and control a well blowout.
Transition from Operation to Blowout
[0102] The transition from operation to blowout is not sudden (for a computer) and may be divided, at least, into two stages: Alert and Alarm. For example, an Alert stage may be triggered by one or more of computer 20 monitored parameters exceeding an Alert threshold, such as, changes in pump speed, excess annulus flow resulting in increased pit volume, lateral motion of the drill pipe (illustrated in
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[0105] At time T3, drill pipe 7 starts moving again toward another location and returns to the center of BOP 4 at time T4. This lateral motion of drill pipe 7 may trigger an Alert if it is not corresponding to an activity on rig 1. At time T5 tool-joint 7A goes through the center of sensor 30 resulting in a signal increase in all four quadrants. The signals may be combined to a single trace for display to the rig crew as shown in
[0106] An Alarm stage may be triggered by one or more of monitored parameters exceeding an Alarm threshold while the rig crew is still in control and the rig is still functional (which can be verified through feedback). A surface computer may display the prescribed steps to deal with the Alarm. It should be noted that there may be a life-threatening urgency to identify the source of the Alarm and act upon it rapidly as it may evolve into a blowout before the rig crew has time to react. For example, if the rig is not tripping out the drill pipe and the drill string starts traveling upwards as illustrated in
the BOP as a Blowout-Arrestor
[0107] Referring back to
[0108] The controlled conditions of the well-operations are no longer valid during a blowout. Instead, they are replaced by the random and erratic conditions imposed by an unpredictable forceful dynamic event, the well blowout. It should be noted that the well blowout parameters may change rapidly and an accurate rapid response is crucial to control the situation. Drill pipe 7 behaviors inside BOP 4 may progress from
[0109] It should also be noted that not all well blowouts behave identically. The unpredictability of a well blowout makes it impossible to program a fixed automatic sequence of BOP 4 to arrest and restrain the blowout. In fact, a fixed automatic sequencing, like the EDS sequence, may worsen the problem. However, prior art BOP's still rely on the fixed EDS sequence to arrest and restrain a blowout (see Macondo reports)—another root-cause of the Macondo and other disaster.
[0110] Generally, one or more of the following situation is true during a blowout:
[0111] the rig crew may not be in control and may be incapacitated which the Auto BOP can ascertain;
[0112] the rig may no longer be functional which the AutoBOP can ascertain;
[0113] the upward flow of hydrocarbons provides the drill pipe controlling force, not the rig, which the AutoBOP can ascertain;
[0114] the drill string may be deformed and under compression which the AutoBOP monitors;
[0115] the drill pipe may be resting on the BOP wall that limits the degree of its deformation which the AutoBOP monitors;
[0116] it is unknown what is inside the BOP shear rams and it varies with time. The AutoBOP knows continuously what-is, how-is and where-is including its critical parameters;
[0117] the drill string is traveling as it is ejected by the blowout fluids and gases which the AutoBOP monitors and calculates a velocity and an acceleration;
[0118] the well is flowing under the control of the formation which the AutoBOP monitors;
[0119] the Blowout-Arrestor sequence can only be formulated by monitoring the blowout evolution;
[0120] shearing force above nominal is required to complete the task; and
[0121] there is a life-threatening urgency to seal the well in the shortest possible time.
[0122] Although the Deepwater Horizon BOP was maintained properly all along, it failed to control the Macondo well blowout in April 2010 because it was designed as an Operations-Aid not a Blowout-Arrestor and therefore, it was not fit-for-purpose and not seaworthy.
Shearing-Force
[0123] BOP manufacturers use distortion energy theory to estimate a shearing-force. Some use the yield strength of the drill pipe and others use the ultimate strength in their calculations; the later providing higher shearing-force estimates. However, neither provides a high enough estimate to cover the worst case scenario as detailed below—yet another root-cause of the Macondo and other disasters.
[0124] For the following analysis it is assumed that an Operations-Aid requires a nominal shearing-force (100%) to shear a high-ductility drill pipe body-wall 7B (See
[0133] It should be understood that the above estimates are cumulative and, again, apply only when the nominal body-wall 7B of the drill pipe 7 is in the shear rams. Therefore, under the conditions detailed above, the Blowout-Arrestor may require 400% the nominal shearing-force of an Operations-Aid for the same drill pipe. It should also be understood that the early intervention of the present invention would reduce the maximum shearing force required. Furthermore, per API S53 (7.6.11.7.5), the maximum shearing pressure should be less than 90% of the maximum operating pressure of the shear ram actuator 5. Therefore, the present invention would incorporate shear rams and actuators 5 to match the cumulative maximum calculated shearing force, not just an estimated nominal. Existing BOPs will be modified accordingly.
Faulty BOP Activation Makes the Blowout Worse
[0134] There are multiple videos and pictures where a well blowout is ejecting the drill string at high speed above the derrick before gravity bends it into a loop as illustrated in
[0135] The time interval from the beginning of the kick until the rig crew recognizes the kick and activates BOP 4 defines the severity of the collision and its repercussion. It is therefore desirable to recognize a kick early on and to react rapidly. The drill pipe upward motion without corresponding rig activity, a sudden off centering (illustrated in
Detailed Description of the AutoBOP Predictive-Controller
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[0137] As discussed previously herein, Sensor interface 27 processes Sensor 30 analog signals and converts said analog signals to a digital format under the control of computer 20. Computer 20 further provides controlled excitation 26. Assuming that sensor 30 comprises of N individual sensors, computer 20 may process said digital signals into N traces around BOP 4 circumference or may combine the signals into eight or four traces as illustrated in
[0138] Referring to
[0139] Referring to
[0140] It should be understood that calculations may be performed using different sensor combinations along sensor 30 plane (x-y) and among different sensors (z). Furthermore, it should be understood that each sensor 30 may comprise similar or different types of individual sensors that may be mounted on an x-y plane perpendicular to BOP 4 vertical axis or be stacked in the z axis or any combination thereof. Different types of sensors may require different excitation 26 and therefore, each sensor 30 may further comprise one or more excitation inducers or the excitation inducers may be mounted separately or any combination thereof.
[0141] Computer 20 may transmit the results to the surface and receive data and commands from the surface or a remote operator through communication link 22. Power and communication subsea connector 23 allows an ROV to restore BOP power, both electrical and hydraulic and operate computer 20 and the peripherals through peripheral-bus 21.
[0142] Computer 20 also processes and assimilates information from a number of Data Acquisition sensors 25 through the data acquisition system 24. Data Acquisition Sensors 25 are disposed around Rig 1 and BOP 4 and may measure capacitance, contactivity, current, deflection, density, external pressure, fluid volume, flow rate, frequency, impedance, inductance, internal pressure, length, rate, accumulator pressure, pressure, resistance, sound, temperature, vibration, voltage, similar items and combinations thereof.
BOP Monitoring
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[0149] It should be understood that although
BOP Control
[0150] Again, BOP 4 is a complex machine that can be operated in multiple ways to achieve a goal while enduring a compendium of (variable) forces and interactions that, most likely, are redefining the goal. However, most often complexity is of low utility. For example, a human does not study all the details of a train before recognizing that it is a train or that the train is moving or not. Instead, humans reduce the myriad of complex train patterns to a simple unique pattern that is a property of trains, as opposed to trucks or airplanes.
[0151] AutoBOP 4 uses the same approach to define the predictive-software whereby, the complex BOP 4 operational states are reduced to a sequence(s) of simple patterns that may be interconnected through an equation or a system of equations (numerical, logic, fuzzy), tables (numerical, logic or fuzzy), other relational operators, similar items and combinations thereof, thus preserving and accounting for the dynamic properties and interactions. It should be noted that AutoBOP 4 operates in a limited space, within limited time (when needed) and has limited resources to solve the Problem.
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[0153] For example, during normal operations, computer 20 may scan each drill pipe joint 7 and store in database critical information in a drill string lengthwise format comprising of wall thickness, imperfections, hardness, dimensions, wear, stress concentration, weight, similar items and combination thereof. Computer 20 may then use the stored critical information to calculate a required nominal shearing force FH along the length of the drill string and may notify the rig crew when it detects drill pipe 7 that exceeds the shearing specifications. It should be understood that computer 20 updates the lengthwise drill string critical information in subsequent scans so that the database comprises of the latest data.
[0154] Computer predictive-software 28 therefore knows in some detail the nominal shearing force required for each drill pipe joint 7 and may translate it to a horizontal force FH acting on shear ram 4SH through piston 5B and thus, the minimum pressure to drive piston 5B. Computer 20 also knows each drill pipe joint 7 below the shear rams and the location of each drill pipe joint 7 in the string; knows the flow rate through communication link 22 and may calculate a Force FV; knows the temperature through the data acquisition system 24 and Data Acquisition sensor 25; knows the drill pipe 7 internal pressure from a surface pressure monitor through communication link 22 and knows the location and angle of the drill pipe 7 through sensors 30 and thus computer 20 may rapidly calculate a corrected shearing force and a minimum pressure to drive piston 5B.
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[0156] When a blowout is detected, predictive software 28 of computer 20 may rapidly decide how to drive piston 5B. When the drill pipe joint 7 enters the shear rams SH, computer 20 only needs to detect a significant deviation from the stored drill pipe joint 7 parameters, its location and any deformation to correct the required shearing force. Since the AutoBOP acts early on, it is not expected that any drill pipe joint 7 will be significantly deformed and thus requiring a lower shearing force. Computer 20 would then select how to drive piston 5B.
[0157] For each selection, there is an associated equation or table or graph that defines the pressure (time) function that drives piston 5B. Drill pipe 7 known dimensions may be translated to piston 5B length travel and therefore, the horizontal Force FH acting upon the drill pipe 7 wall. If computer 20 determines that the accumulator 11B pressure is not adequate to shear the drill pipe 7, computer 20 may switch the shear rams 4SH piston 5B to pressure intensifier 12B. Computer 20 will close valve 14B and open valves 13B and 15B. Computer 20 may do so in advance in anticipation of the next drill pipe joint 7.
[0158] The time interval between tool joints 7A of
[0159] Again, an EDS/Deadman sequence will activate annular preventer 4C first resulting in a collision with a tool-joint 7A and trapping the results of the collision inside BOP 4 below annular preventer 4C. Instead, for example, properly timed rapid sequencing of pipe ram 4A followed by annular preventer 4C and then by shear ram 4B would place drill pipe wall 7B inside shear rams 4B and the results of tool-joint 7A collision with pipe ram 4A below BOP 4. In addition, the momentum of the traveling drill string above pipe ram 4A may temporarily place the drill pipe inside shear ram 4B under tension. It should also be understood that AutoBOP 40 reaction would take place at the initial stages of a blowout where forces and momentum is still low enough to control. It should be noted that an estimation of the drill string momentum may be easily calculated from the string weight by adding the weight of each drill pipe joint 7 and the speed of the drill string.
When Things Still Go Wrong
[0160] The above calculations however ignore the absence of the beneficial tension that makes certain BOP actions ineffective [see API S53 (7.6.11.7.11)]. The Blowout-Arrestor of the present invention increases the shearing-force and adds a tearing-force to drill pipe 7. During a blowout, shear ram 4B may be driven by pressure intensifier(s) 12B and pipe ram 4A may be driven to a lateral oscillation to aid the tearing of the drill pipe inside shear ram 4B through cumulative fatigue. Even a small-magnitude oscillation would focus on the stress-concentrator that was created by shear ram 4B. Pipe ram 4A surface may utilize a pipe gripper to prevent slippage and may incorporate an actuator with extended reach. The lateral oscillation will also require higher actuator pressure and volume. It should be understood that the lateral oscillation of pipe ram 4A may undermine the shearing force of shear ram 4B and therefore, the AutoBOP would apply corrective pressure or a locking mechanism to shear ram 4B.
[0161] Notice that shearing is not possible if a tool-joint or heavy wall OCTG is in the shear rams although the need to seal-off the well is still the same. This may be overcome by: the use of two shear rams, also specified in API S53 (7.1.3.1.6). In the present invention, two shear rams would be spaced further apart than the [(longest tool-joint length)+(upset area length)] to assure that there is no tool joint in at least one of the shear rams. The AutoBOP would then activate only the shear ram to cut the body wall. In the event that nonshearable equipment is inside the shear rams, the AutoBOP adds a hammer operation to the operation of shear ram 4B. The hammer operation may be carried out through control of the hydraulic supply or through a motor or a combination thereof. It should be understood that the hammer operation will also require an actuator with higher operational pressure.
[0162] The corrective steps 1 through 4 may be implemented through computer 20 or through external control (such as an ROV) and may be carried out using the existing electrical and hydraulic connections of rig 1, BOP 4 batteries and accumulators, subsea connectors, similar items and combinations thereof.
[0163] In other embodiments, a system to arrest and control an elastically unstable slender column of material is provided that may comprise components such as but not limited to at least one computer with a sensor interface, at least one sensor to monitor parameters of the material inside the system,
[0164] at least one ram with an accumulator, and/or a program being executed on the at least one computer to activate the at least one ram to control the column of material, the activation been partially controlled by the monitored parameters.
[0165] The parameters may comprise of wall thickness, imperfections, hardness, dimensions, wear, rate of wear, stress concentration, weight, lateral location, angle, similar items and a combination thereof.
[0166] The at least one computer may further comprise of a data acquisition system to monitor operation parameters of the system.
[0167] The operation parameters may comprise of one or more of capacitance, contactivity, current, deflection, density, external pressure, fluid volume, flow rate, frequency, impedance, inductance, internal pressure, length, accumulator pressure, resistance, sound, temperature, vibration, voltage, similar items and combinations thereof.
[0168] The activation may be partially controlled responsively to the monitored operation parameters.
[0169] Another embodiment may comprise a system to arrest and control an elastically unstable slender column of OCTG. The system may comprise of but is not limited to at least one computer, a data acquisition system to monitor operational parameters of the system, at least one ram with a accumulator, and/or a program being executed on the at least one computer to activate the at least one ram to control the column of OCTG. The activation may be partially controlled in response to the monitored operational parameters.
[0170] The operation parameters may comprise of one or more of capacitance, contactivity, current, deflection, density, external pressure, fluid volume, flow rate, frequency, impedance, inductance, internal pressure, length, accumulator pressure, resistance, sound, temperature, vibration, voltage, similar items and combinations thereof.
[0171] The at least one computer of may further comprise of a sensor interface to monitor parameters of the material inside the system.
[0172] The material parameters may comprise of wall thickness, imperfections, hardness, dimensions, wear, rate of wear, stress concentration, weight, lateral location, angle, similar items and/or a combination thereof.
[0173] The activation may be partially controlled responsively to the monitored material parameters.
[0174] In another embodiment, a constant-vigilance well-monitoring system may comprise of but is not limited to at least one computer, at least one sensor operable by the at least one computer to monitor at least one operational parameter of the well and a program being executed on the at least one computer to process the at least one operational parameter to determine a status of the well.
[0175] The operation parameters may comprise of one or more of acceleration, angle, capacitance, contactivity, current, deflection, deformation, density, dimension, field, flow rate, fluid volume, frequency, GPS, hardness, impedance, imperfection, inductance, intensity, length, light, location, motion, pressure, resistance, sound, speed, temperature, vibration, voltage, wall thickness, imperfections , weight, similar items and combinations thereof.
[0176] The at least one computer may further control excitation for the at least one sensor, which may or may not also comprise pipe magnetization.
[0177] The well-monitoring system may further comprise of at least one valve under the control of the at least one computer. The at least one valve may be capable of reducing the cross-sectional-area of the annulus of the well. The at least one valve may be capable of diverting the flow of the well.
[0178] The system whereby the activation may be partially controlled responsively to the monitored material parameters.
[0179] In yet another embodiment, a system to monitor hydrocarbon well conditions may comprise various status features comprising the rig crew is in control; the rig is functioning; the rig provides the drill pipe controlling force; the drill string is straight and under tension; the drill pipe is near the center of the BOP; the rig crew may position a drill pipe body-wall inside the shear rams; the drill string is static; the well is not flowing or the flow is under the control of the rig crew; the BOP sequencing, like the EDS sequence, may be programmed and carried-out automatically; and there is no life-threatening urgency to complete the task.
[0180] The parameters may comprise of wall thickness, imperfections, hardness, dimensions, wear, rate of wear, stress concentration, weight, lateral location, angle, similar items and a combination thereof.
[0181] In general, it will be understood that such terms as “up,” “down,” “vertical,” “upper”, “lower”, “above”, “below”, and the like, are made with reference to the drawings and/or the earth and that the devices may not be arranged in such positions at all times depending on variations in operation, transportation, mounting, and the like. As well, the drawings are intended to describe the concepts of the invention so that the presently preferred embodiments of the invention will be plainly disclosed to one of skill in the art but are not intended to be manufacturing level drawings or renditions of final products and may include simplified conceptual views as desired for easier and quicker understanding or explanation of the invention. One of skill in the art upon reviewing this specification will understand that the relative size and shape of the components may be greatly different from that shown and the invention can still operate in accord with the novel principals taught herein. While inner and outer seals are created as shown above, only an inner or outer seal might be created in accord with the present invention.
[0182] Accordingly, because many varying and different embodiments may be made within the scope of the inventive concept(s) herein taught, and because many modifications may be made in the embodiment herein detailed in accordance with the descriptive requirements of the law, it is to be understood that the details herein are to be interpreted as illustrative of a presently preferred embodiment and not in a limiting sense.