A managed pressure drilling system

Abstract

A kind of managed pressure drilling system, including drilling pump, automatic throttle manifold module, circulating tank, drilling drilling tool, main flow module and bypass shunt module;Drilling drilling tool includes rotary control head, for forming wellbore annulus kill line and throttle line;Main flow module includes main flow pipeline and the main flow valve group being installed on main flow pipeline;Bypass flow module includes bypass flow pipeline and the bypass flow valve group being installed on bypass flow pipeline;Automatic throttle manifold module includes throttle pipeline and the throttle valve group being arranged on the throttle pipeline;The present application avoids the use of back pressure pump system by the setting of bypass shunt module, reduces the failure rate of the managed pressure drilling system during drilling process, reduces the complexity of field equipment connection.

Description

Technical Field

[0001] This invention relates to the field of controlled pressure drilling, and in particular to a controlled pressure drilling system. Background Technology

[0002] Oil and gas development is increasingly operating in complex formations. Complex formations typically have a small difference between collapse and fracture pressures, or a narrow drilling fluid safety density window. When using conventional drilling techniques, blowouts, leaks, stuck pipe, and collapses are common. To ensure safe drilling operations and reduce accidents, controlled pressure drilling (CPD) technology is frequently used. One method of CPD is to indirectly control bottom hole pressure by controlling wellhead back pressure. A core technology and piece of equipment is the controlled pressure automatic choke manifold. Using the controlled pressure automatic choke manifold allows for precise control of wellhead back pressure, indirectly achieving rapid and precise control of bottom hole pressure. A key characteristic of CPD is maintaining a constant bottom hole pressure by applying back pressure at the wellhead to compensate for the frictional resistance of the drilling fluid in the wellbore. Therefore, regardless of whether the drilling pump is on or off, the bottom hole pressure in CPD remains constant.

[0003] Currently, wellhead back pressure in controlled pressure drilling is provided by a back pressure pump system. This system consists of a drilling pump, motor, frequency converter, and control system. The control system is complex and costly. Using a back pressure pump system significantly increases operating costs during production. Furthermore, back pressure pumps typically have a small displacement, insufficient to meet drilling fluid replenishment needs during tripping operations for extended periods. Frequent starts and stops of the back pressure pump system also increase the susceptibility of the frequency converter and control system to failure, often forcing drilling operations to halt.

[0004] Meanwhile, during the on-site tripping or connection of single sections, drilling fluid on the drilling platform may splash onto the rotary control head and blowout preventer assembly, and drip onto the ground or seawater, causing equipment safety hazards and environmental pollution. Summary of the Invention

[0005] In view of the shortcomings of the prior art described above, the technical problem to be solved by the present invention is to provide a controlled pressure drilling system that reduces the complexity of field equipment connections and improves the reliability of equipment use.

[0006] This invention proposes a controlled-pressure drilling system, comprising a drilling pump, an automatic choke manifold module, a circulation tank, drilling tools, a main flow module, and a bypass flow module. The drilling tools include a rotary control head, a kill line for forming the wellbore annulus, and a choke line. The main flow module includes a main flow pipe and a main flow valve assembly installed on the main flow pipe. The bypass flow module includes a bypass flow pipe and a bypass flow valve assembly installed on the bypass flow pipe. The automatic choke manifold module includes a choke pipe and a choke valve assembly installed on the choke pipe. The inlet of the main flow module and the inlet of the bypass flow module are both connected to the outlet of the drilling pump, and the inlet of the drilling pump is connected to the outlet of the circulation tank. The inlet of the rotary control head is connected to the outlet of the main flow module, and the outlet of the rotary control head is connected to the inlet of the automatic choke manifold module. The outlet of the bypass flow module is connected to the inlet of the kill line, and the outlet of the choke line is connected to the inlet of the automatic choke manifold module. The automatic choke manifold module is connected to the inlet of the circulation tank.

[0007] Preferably, the main flow valve group includes a main flow regulating valve, the bypass flow valve group includes a bypass flow regulating valve, and the automatic throttling valve group includes a throttling regulating valve.

[0008] Preferably, the main flow valve group further includes a main flow shut-off valve connected in series with the main flow regulating valve, the bypass flow valve group further includes a bypass flow shut-off valve connected in series with the bypass flow regulating valve, the automatic throttling valve group further includes a throttling bypass shut-off valve connected in parallel with the throttling regulating valve, and a first throttling shut-off valve and a second throttling shut-off valve respectively connected in series before and after the throttling regulating valve.

[0009] Preferably, the controlled pressure drilling system further includes a monitoring module, wherein the main flow regulating valve, the bypass flow regulating valve, and the throttling regulating valve are all electric or pneumatic valves; an inlet flow meter is provided at the outlet end of the main flow pipeline, and an outlet flow meter is provided at the outlet end of the throttling pipeline; the main flow regulating valve, the bypass flow regulating valve, the throttling regulating valve, the inlet flow meter, and the outlet flow meter are all communicatively connected to the monitoring module.

[0010] Preferably, the inlet flow meter is an ultrasonic flow meter, and the outlet flow meter is a mass flow meter.

[0011] Preferably, the outlet of the main flow module is connected to the inlet of the circulation tank via a drain pipe, and a drain valve is provided on the circulation pipe.

[0012] Preferably, the drilling tool further includes an oil-water lubrication system for the rotary control head and a drilling fluid collection device. The rotary control head includes a rotary seal assembly, a quick connector, a base, and a base locking device. The quick connector is used to connect to the oil-water lubrication system of the rotary control head. The rotary seal assembly is used to seal the opening of the quick connector. The base locking device locks the rotary seal assembly onto the base. The drilling fluid collection device includes a shielding plate mounted on the rotary seal assembly and covering the rotary seal assembly, and an annular groove fixed on the base. The annular groove is arranged around the rotary seal assembly, and the outer edge of the shielding plate extends into the opening of the annular groove.

[0013] Preferably, the drilling fluid collection device further includes a flow guide shroud, which opens upward from the outer wall of the annular groove to collect drilling fluid.

[0014] As described above, the controlled pressure drilling system of the present invention has the following beneficial effects: the present invention avoids the use of back pressure pump system by setting a bypass diversion module, thereby reducing the failure rate of the controlled pressure drilling system and reducing the complexity of field equipment connection during the drilling process. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of a pressure-controlled drilling system according to the present invention.

[0016] Figure 2 This is a schematic diagram of the drilling fluid collection device installed on the rotary control head in this invention.

[0017] Explanation of reference numerals in the attached figures:

[0018] 100. Drilling pump; 200. Main flow module; 210. Main flow pipeline; 221. Main flow regulating valve; 222. Main flow shut-off valve; 230. Inlet flow meter; 300. Bypass diversion module; 310. Bypass flow pipeline; 321. Bypass flow regulating valve; 322. Bypass flow shut-off valve; 400. Drilling tools; 410. Rotary control head; 411. Rotary seal assembly; 412. Quick coupling; 413. Base; 414. Base locking device; 420. Kill line; 421. Throttling line; 500, Automatic throttling manifold module; 510, Throttling pipeline; 521, Throttling regulating valve; 522, First throttling shut-off valve; 523, Second throttling shut-off valve; 524, Throttling bypass shut-off valve; 530, Outlet flow meter; 600, Circulation tank; 610, Drilling fluid treatment device; 700, Drainage pipeline; 710, Drainage valve; 800, Monitoring module; 900, Drilling fluid collection device; 910, Baffle plate; 920, Annular groove; 930, Flow guide; 940, Collection device mounting base. Detailed Implementation

[0019] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification.

[0020] It should be understood that the structures, proportions, sizes, etc., illustrated in the accompanying drawings of this specification are merely for illustrative purposes to aid those skilled in the art and are not intended to limit the scope of the invention. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness and purpose of the invention, should still fall within the scope of the technical content disclosed in this invention. Furthermore, the terms such as "upper," "lower," "left," "right," and "middle" used in this specification are merely for clarity and are not intended to limit the scope of the invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention.

[0021] like Figure 1 As shown, an embodiment of the present invention provides a controlled pressure drilling system, including a drilling pump 100, an automatic choke manifold module 500, a circulation tank 600, a drilling tool 400, a main flow module 200, and a bypass diversion module 300; the drilling tool 400 includes a rotary control head 410, a kill line 420 for forming the wellbore annulus, and a choke line 421; the main flow module 200 includes a main flow pipe 210 and a main flow valve assembly installed on the main flow pipe 210; the bypass flow module includes a bypass flow pipe 310 and a bypass flow valve assembly installed on the bypass flow pipe 310; the automatic choke manifold module 500 includes a choke pipe 510 and a choke valve assembly installed on the choke pipe 510;

[0022] The inlet of the main flow module 200 and the inlet of the bypass diversion module 300 are both connected to the outlet of the drilling pump 100. The inlet of the drilling pump 100 is connected to the outlet of the circulation tank 600. The inlet of the rotary control head 410 is connected to the outlet of the main flow module 200. The outlet of the rotary control head 410 is connected to the inlet of the automatic choke manifold module 500. The outlet of the bypass diversion module 300 is connected to the inlet of the kill line 420. The outlet of the choke line 421 is connected to the inlet of the automatic choke manifold module 500. The automatic choke manifold module 500 is connected to the inlet of the circulation tank 600.

[0023] In normal drilling mode, drilling fluid is drawn from circulation tank 600 by drilling pump 100, pressurized, and then flows through main flow pipe 210, through rotary control head 410, through riser, into automatic choke manifold module 500, and finally into circulation tank 600. At this time, bypass flow pipe 310 is shut off, that is, bypass flow valve group is closed.

[0024] In single-connection and tripping modes, based on the wellbore annular fluid level requirements, a portion of the drilling fluid enters through the kill line 420 and flows out through the choke line 421 to form the wellbore annulus. The pressure-controlled automatic choke manifold returns the fluid to the drilling fluid pool, maintaining constant pressure at the bottom of the well. At this time, the main flow line 210 is closed, meaning the main flow valve group is shut off, and the bypass flow line 310 is opened. The drilling fluid is drawn from the circulation tank 600 by the drilling pump 100, pressurized, and then enters the automatic choke manifold module 500 through the bypass flow line 310, ultimately entering the circulation tank 600. Preferably, the inlet of the circulation tank 600 is also equipped with a drilling fluid treatment device 610 to treat the drilling fluid entering the circulation tank 600, ensuring that the cleanliness of the drilling fluid meets the standards.

[0025] This embodiment avoids the use of the back pressure pump system by setting up the bypass diversion module 300, thereby reducing the failure rate of the controlled pressure drilling system and reducing the complexity of on-site equipment connections during the drilling process.

[0026] The main flow valve assembly includes a main flow regulating valve 221, the bypass flow valve assembly includes a bypass flow regulating valve 321, and the automatic throttling valve assembly includes a throttling regulating valve 521. By adjusting the main flow regulating valve 221, the bypass flow regulating valve 321, and the throttling regulating valve 521, the flow rate of drilling fluid in each passage can be controlled, thereby ensuring that the bottom hole pressure remains constant in pressure controlled drilling technology.

[0027] The main flow valve group also includes a main flow shut-off valve 222 connected in series with the main flow regulating valve 221. The bypass flow valve group also includes a bypass flow shut-off valve 322 connected in series with the bypass flow regulating valve 321. The automatic throttling valve group also includes a throttling bypass shut-off valve 524 connected in parallel with the throttling regulating valve 521, and a first throttling shut-off valve 522 and a second throttling shut-off valve 523 connected in series before and after the throttling regulating valve 521, respectively. The main flow shut-off valve 222, the bypass flow shut-off valve 322, the first throttling shut-off valve 522, and the second throttling shut-off valve 523 are all used to shut off the corresponding flow pipelines.

[0028] Therefore, when the controlled pressure drilling system is in normal drilling mode, the main flow regulating valve 221, the main flow shut-off valve 222, the first throttle shut-off valve 522, and the second throttle shut-off valve 523 are all open, while the bypass flow shut-off valve 322 is closed. When the controlled pressure drilling system is in single-joint or tripping mode, the bypass flow regulating valve, the bypass flow shut-off valve 322, the first throttle shut-off valve 522, and the second throttle shut-off valve 523 are all open, while the main flow shut-off valve 222 is closed.

[0029] The controlled pressure drilling system also includes a monitoring module 800. The main flow regulating valve 221, the bypass flow regulating valve 321, and the throttling regulating valve 521 are all electric or pneumatic valves. An inlet flow meter 230 is installed at the outlet end of the main flow pipeline 210, and an outlet flow meter 530 is installed at the outlet end of the throttling pipeline 510. The main flow regulating valve 221, the bypass flow regulating valve 321, the throttling regulating valve 521, the inlet flow meter 230, and the outlet flow meter 530 are all communicatively connected to the monitoring module 800.

[0030] The monitoring module 800 monitors the operating parameters of the drilling tools 400, the main flow module 200, the bypass flow module, and the automatic choke manifold module 500. It controls the opening and closing of the main flow pipe 210 and the bypass flow pipe, and adjusts the opening of the choke regulating valve 521 in the automatic choke manifold module 500 to achieve wellbore pressure and flow control. In addition to collecting data from the inlet flow meter 230 and the outlet flow meter 530 in real time, the monitoring module 800 also continuously collects conventional drilling parameters such as standpipe pressure, casing pressure, downhole pressure, and logging data. Based on these parameters, it controls the states of the main flow regulating valve 221, the bypass flow regulating valve 321, and the choke regulating valve 521 to maintain the bottom hole pressure within the design pressure range. Preferably, the inlet flow meter 230 is an ultrasonic flow meter, and the outlet flow meter 530 is a mass flow meter.

[0031] It should be noted that the outlet of the main flow module 200 is connected to the inlet of the circulation tank 600 via a drain pipe 700, and a drain valve 710 is installed on the circulation pipe. When the pressure-controlled drilling system stops working, the drilling fluid remaining in the drilling tools can be discharged into the circulation tank through the drain pipe 700.

[0032] like Figure 1 and 2 As shown, the drilling tool 400 in this embodiment also includes an oil-water lubrication system for the rotary control head 410. The rotary control head 410 includes a rotary seal assembly 411, a quick connector 412, a base 413, and a base 413 locking device. The quick connector 412 is used to connect to the oil-water lubrication system of the rotary control head 410 power station. The rotary seal assembly 411 is used to seal the opening of the quick connector 412. The base 413 locking device locks the rotary seal assembly 411 onto the base 413. The drilling fluid collection device 900 includes a shielding plate 910 covering the rotary seal assembly 411 and an annular groove 920 fixed on the base 413. The annular groove 920 is arranged around the rotary seal assembly 411, and the outer edge of the shielding plate 910 extends into the opening of the annular groove 920.

[0033] During drilling, drilling fluid sliding off the drilling platform lands on the baffle plate 910 and flows into the annular groove 920 from the edge of the baffle plate 910, thus collecting the drilling fluid and preventing damage to the rotary seal assembly 411 and contamination of the oil-water lubrication system of the rotary control head 410. Alternatively, guide holes can be machined on the bottom of the annular groove 920, and a hose can be used to guide the drilling fluid collected in the annular groove 920 to the circulation tank 600. The drilling fluid collection device 900 also includes a guide shield 930, which opens upward from the outer wall of the annular groove 920 to collect the drilling fluid, allowing more drilling fluid to enter the annular groove 920. The drilling fluid collection device 900 also includes a collection device mounting base 940, which fixes the drilling fluid collection device 900 to the base 413.

[0034] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A controlled-pressure drilling system, characterized in that, The system includes a drilling pump (100), an automatic choke manifold module (500), a circulation tank (600), drilling tools (400), a main flow module (200), and a bypass diversion module (300); the drilling tools (400) include a rotary control head (410) and a kill line (420) and a choke line (421) for forming the wellbore annulus; the main flow module (200) includes a main flow pipe (210) and a main flow valve assembly installed on the main flow pipe (210); the bypass diversion module includes a bypass flow pipe (310) and a bypass flow valve assembly installed on the bypass flow pipe (310); the automatic choke manifold module (500) includes a choke pipe (510) and a choke valve assembly installed on the choke pipe (510); The inlet of the main flow module (200) and the inlet of the bypass diversion module (300) are both connected to the outlet of the drilling pump (100), and the inlet of the drilling pump (100) is connected to the outlet of the circulation tank (600); the inlet of the rotary control head (410) is connected to the outlet of the main flow module (200), the outlet of the rotary control head (410) is connected to the inlet of the automatic choke manifold module (500), the outlet of the bypass diversion module (300) is connected to the inlet of the kill line (420), the outlet of the choke line (421) is connected to the inlet of the automatic choke manifold module (500), and the outlet of the automatic choke manifold module (500) is connected to the inlet of the circulation tank (600); The main flow valve group includes a main flow regulating valve (221), the bypass flow valve group includes a bypass flow regulating valve (321), and the throttle valve group includes a throttle regulating valve (521). The main flow valve group also includes a main flow stop valve (222) connected in series with the main flow regulating valve (221), the bypass flow valve group also includes a bypass flow stop valve (322) connected in series with the bypass flow regulating valve (321), the throttle valve group also includes a throttle bypass stop valve (524) connected in parallel with the throttle regulating valve (521), and a first throttle stop valve (522) and a second throttle stop valve (523) connected in series before and after the throttle regulating valve (521); The outlet of the main flow module (200) is connected to the inlet of the circulation tank (600) via an emptying pipe (700), and an emptying valve (710) is provided on the emptying pipe; The drilling tool (400) also includes an oil-water lubrication system for a rotary control head (410) and a drilling fluid collection device (900). The rotary control head (410) includes a rotary seal assembly (411), a quick connector (412), a base (413), and a base (413) locking device. The quick connector (412) is used to connect to the oil-water lubrication system of the rotary control head (410). The rotary seal assembly (411) is used to seal the opening of the quick connector (412). The base (413) locking device locks the rotary seal assembly (411) onto the base (413). The drilling fluid collection device (900) includes a shielding plate (910) covering the rotary seal assembly (411) and an annular groove (920) fixed on the base (413). The annular groove (920) is arranged around the rotary seal assembly (411), and the outer edge of the shielding plate (910) extends into the opening of the annular groove (920). The drilling fluid collection device (900) also includes a flow guide (930), which opens upward from the outer wall of the annular groove (920) for collecting drilling fluid.

2. The controlled pressure drilling system according to claim 1, characterized in that, The controlled pressure drilling system also includes a monitoring module (800). The main flow regulating valve (221), the bypass flow regulating valve (321), and the throttling regulating valve (521) are all electric or pneumatic valves. An inlet flow meter (230) is provided at the outlet end of the main flow pipeline (210), and an outlet flow meter (530) is provided at the outlet end of the throttling pipeline (510). The main flow regulating valve (221), the bypass flow regulating valve (321), the throttling regulating valve (521), the inlet flow meter (230), and the outlet flow meter (530) are all communicatively connected to the monitoring module (800).

3. A pressure-controlled drilling system according to claim 2, characterized in that, The inlet flow meter (230) is an ultrasonic flow meter, and the outlet flow meter (530) is a mass flow meter.

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