Deepwater pressure control drilling subarea well control method and drilling platform system thereof

Abstract

The invention relates to a deepwater pressure-controlled drilling zoning well control method which comprises the following steps: when a marine riser annular space formed by a pressure-controlled drilling rotary control head and a platform seabed blowout preventer is in a vertically closed state, testing pump pressure values of a circulation path under different displacements of a drilling augmented injection pump; the pressure at the bottom of the marine riser is controlled to be kept as the target pressure, and the gas cut drilling fluid in the marine riser annulus is discharged; the target pressure is obtained by subtracting bottom hole pressure from formation pressure, and the bottom hole pressure is the sum of circulating pressure consumption and hydrostatic column pressure; the pumping pressure value is used as the circulating pressure consumption; heavy slurry is injected into the marine riser annulus; and opening the seabed blowout preventer, and turning into normal operation. The invention further discloses a pressure control drilling platform system. By the adoption of the control method, no gas enters the marine riser again when the gas cut drilling fluid is discharged, and the situation that a drilling tool in a well is still for a long time is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of submarine drilling, and more specifically, to a deepwater managed pressure drilling zoned well control method and a drilling platform system thereof. Background Art

[0002] At present, the research and development of deepwater controlled pressure drilling technology and equipment in China is in its infancy. The exploration and development of deepwater deep-layer oil and gas resources faces many challenges such as high temperature, high pressure, and narrow safety density window. The blowout preventer group of deepwater drilling is installed on the seabed. The blowout preventer group is connected to the deepwater drilling platform through a watertight pipe and a drilling fluid circulation passage is established. If conventional deepwater drilling operations encounter gas invasion problems, it is difficult to detect gas invasion in time using conventional monitoring methods. When the monitoring equipment detects gas invasion, the gas may have entered the watertight pipe. In order to safely and effectively control the downhole situation, the drilling platform will close the seabed blowout preventer group and perform well control operations. The gas entering the watertight pipe will further slip and expand in the watertight pipe, and the circulation passage of the deepwater drilling platform diverter and liquid-gas separator cannot control the reflux speed, which will seriously cause the gas in the watertight pipe to expand, causing damage to ground equipment and personnel.

[0003] The prior art discloses a method for handling gas intrusion in a riser, providing an improved way to control gas expansion in a marine riser, and further providing an improved method and device for restoring hydrostatic control of a riser after gas intrusion into the riser. However, the solution has the following shortcomings:

[0004] (1) The gas-invaded drilling fluid in the riser is diverted to the diverter and liquid-gas separator on the platform through the gas handling manifold of the riser. The diverter is an annular sealing device, usually used in low-pressure systems (200psi to 500psi working pressure); in addition, after monitoring and detecting gas invasion, the closing time of the diverter is 30 to 45 seconds. During this time, gas still enters the riser, which increases the gas handling volume and handling difficulty.

[0005] (2) The riser control device was improved, and an annular blowout preventer was installed below the riser expansion joint. When the annular blowout preventer seals the drill string-riser annulus, the drill string cannot rotate or move up and down, causing the drilling tools in the well to remain stationary for a long time, which can easily induce complex situations downhole.

[0006] (3) When dealing with gas intrusion in the riser and gas intrusion in the wellbore below the subsea blowout preventer, the platform's throttle manifold must be used, which makes it impossible to deal with the gas intrusion problems in the above two situations at the same time. Summary of the invention

[0007] In order to overcome the problems in the prior art that the gas intrusion problem is difficult to handle and is prone to other problems, the present invention provides a deepwater controlled pressure drilling zoned well control method to achieve safe and controllable removal of gas in the watertight pipe.

[0008] In order to solve the above technical problems, the technical solution adopted by the present invention is: a deepwater managed pressure drilling zone well control method, comprising the following steps:

[0009] Step 1: When the annular space of the riser formed by the pressure-controlled drilling rotary control head and the platform seabed blowout preventer is in a closed state, test the pump pressure value of the circulation passage at different displacements of the drilling booster pump;

[0010] Step 2: Control the pressure at the bottom of the riser to maintain the target pressure and discharge the gas-invaded drilling fluid in the riser annulus; the target pressure is the formation pressure minus the bottom hole pressure, and the bottom hole pressure is the sum of the circulation pressure loss and the static liquid column pressure; the pump pressure value is the circulation pressure loss;

[0011] Step 3: Inject heavy slurry into the riser annulus;

[0012] Step 4: Open the subsea blowout preventer and return to normal operation.

[0013] In the above technical scheme, after closing the seabed blowout preventer, the formation products will no longer enter the riser; according to the U-tube principle, the riser annulus and the riser injection side pipe are used as the two sides of the U-tube. Since the riser is filled with gas-invaded drilling fluid, it is necessary to calculate the riser bottom pressure through one side of the injection side pipe (one side of the injection side pipe is filled with pure drilling fluid, and this pressure is the target pressure, the riser bottom pressure = injection pump circulation riser pressure - injection side pipe circulation pressure loss + injection side pipe drilling fluid static liquid column pressure). In actual field operations, the riser bottom pressure is kept constant by controlling the injection pump riser pressure to be constant (i.e., riser pressure control), and finally the gas-invaded drilling fluid in the riser can be discharged.

[0014] Preferably, in step 1, 1 / 4 to 1 / 3 of the normal displacement of the drilling booster pump during drilling is used as the test displacement for testing, and the obtained pump pressure value is equal to the circulating pressure loss. 1 / 4 to 1 / 3 of the normal displacement of the drilling booster pump during drilling is used as the test displacement for circulation, and the bottom pressure of the riser is used as the target value to use the data of the low pump speed test and the pressure-controlled drilling surface throttle manifold to achieve safe and controllable discharge of the gas-invaded drilling fluid in the riser.

[0015] Preferably, the displacement test in step 1 adopts a low pump speed test method.

[0016] Preferably, in step 2, the pressure at the bottom of the riser is adjusted by a throttle valve on a throttle manifold dedicated to pressure-controlled drilling, so that the pressure at the bottom of the riser is maintained at a target pressure.

[0017] Preferably, in step three, the specific process is: after the wellbore below the seabed blowout preventer is pressured and filled with heavy slurry, the volume of heavy slurry required for the riser annulus is calculated, and the heavy slurry is injected into the riser annulus through the drilling booster pump.

[0018] Preferably, in step three, the heavy slurry pumped by the drilling booster pump is injected into the annulus of the riser from the bottom of the riser through the booster side pipe.

[0019] Preferably, in step 4, after confirming that the upper and lower pressures of the subsea blowout preventer are balanced, the subsea blowout preventer is opened.

[0020] A pressure-controlled drilling platform system is also provided for realizing the above-mentioned deep-water pressure-controlled drilling zoned well control method, including a deep-water pressure-controlled drilling device and a platform circulation system; the deep-water pressure-controlled drilling device includes a pressure-controlled drilling rotary control head, a pressure-controlled drilling diversion spool, a pressure-controlled drilling diversion pipeline and a pressure-controlled drilling special throttling manifold; the platform circulation system includes a drilling injection pump, a water-rising pipe, an injection side pipe and a liquid-gas separator; the deep-water pressure-controlled drilling device is installed on the water-rising pipe, one end of the drilling rotary control head is connected to the upper section of the water-rising pipe, and the other end is connected to the pressure-controlled drilling The well diversion spool is connected, the other end of the pressure controlled drilling diversion spool is connected to the lower section of the riser, the pressure controlled drilling diversion pipeline is connected to the pressure controlled drilling diversion spool, the special throttling manifold for pressure controlled drilling is connected to the pressure controlled drilling diversion pipeline, and the outlet end of the special throttling manifold for pressure controlled drilling is connected to the liquid-gas separator; the injection side pipe is installed outside the riser and connected to the bottom of the riser, the bottom of the lower end of the riser is used to connect to the subsea blowout preventer, and the drilling injection pump is connected to the injection side pipe located at the upper end of the riser.

[0021] Furthermore, a throttle valve for adjusting pressure is installed on the throttle manifold dedicated for pressure-controlled drilling.

[0022] Furthermore, the throttling manifold dedicated to pressure-controlled drilling includes a first regulating pipeline, a second regulating pipeline and an emergency pipeline arranged in parallel, the first regulating pipeline, the second regulating pipeline and the emergency pipeline are all provided with two manual valves, and the first regulating pipeline and the second regulating pipeline are also provided with the throttling valve.

[0023] Compared with the prior art, the beneficial effect of the present invention is that by adopting this control method, after closing the subsea blowout preventer, the gas-invaded drilling fluid in the riser can be safely and controllably discharged and replaced with heavy slurry. In this process, the pressure balance is maintained by controlling the pressure at the bottom of the riser. When discharging the gas-invaded drilling fluid, no gas will enter the riser again, and the drilling equipment in the well will not be stationary for a long time. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1It is a structural schematic diagram of a pressure-controlled drilling platform system of the present invention;

[0025] Figure 2 The present invention is a flowchart of a deepwater controlled pressure drilling zoned well control method. DETAILED DESCRIPTION

[0026] The drawings are only for illustrative purposes and cannot be construed as limiting the present invention. To better illustrate the present embodiment, some parts of the drawings may be omitted, enlarged, or reduced, and do not represent the size of the actual product. For those skilled in the art, it is understandable that some well-known structures and their descriptions may be omitted in the drawings. The positional relationships described in the drawings are only for illustrative purposes and cannot be construed as limiting the present invention.

[0027] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right", "long", "short" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, they are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes and cannot be understood as limitations on this patent. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0028] The technical solution of the present invention is further described in detail below through specific embodiments and in conjunction with the accompanying drawings:

[0029] Example 1

[0030] like Figure 1The figure shows an embodiment of a pressure-controlled drilling platform system, including a deep-water pressure-controlled drilling device and a platform circulation system; the deep-water pressure-controlled drilling device includes a pressure-controlled drilling rotary control head 1, a pressure-controlled drilling diversion spool 2, a pressure-controlled drilling diversion pipeline 3 and a pressure-controlled drilling special throttling manifold 4; the platform circulation system includes a drilling injection pump 5, a water-receiving pipe 6, an injection side pipe 7 and a liquid-gas separator 8; the deep-water pressure-controlled drilling device is installed on the water-receiving pipe 6, one end of the drilling rotary control head is connected to the upper section of the water-receiving pipe 6, and the other end is connected to the pressure-controlled drilling diversion spool 2, and the control The other end of the pressure-controlled drilling diversion spool 2 is connected to the lower section of the riser 6, the pressure-controlled drilling diversion pipeline 3 is connected to the pressure-controlled drilling diversion spool 2, the pressure-controlled drilling special throttling manifold 4 is connected to the pressure-controlled drilling diversion pipeline 3, and the outlet end of the pressure-controlled drilling special throttling manifold 4 is connected to the liquid-gas separator 8; the injection side pipe 7 is installed outside the riser 6 and is connected to the bottom of the riser 6, the bottom of the lower end of the riser 6 is used to connect to the subsea blowout preventer, and the drilling injection pump 5 is connected to the injection side pipe 7 located at the upper end of the riser 6.

[0031] In this embodiment, the throttle manifold 4 for controlled pressure drilling includes a first regulating pipeline 401, a second regulating pipeline 402 and an emergency pipeline 403 arranged in parallel, the first regulating pipeline 401, the second regulating pipeline 402 and the emergency pipeline 403 are each provided with two manual valves, and the first regulating pipeline 401 and the second regulating pipeline 402 are also provided with the throttle valve 9. The throttle valve 9 for regulating pressure is installed on the throttle manifold 4 for controlled pressure drilling.

[0032] The controlled pressure drilling platform system of this embodiment is consistent with the controlled pressure drilling platform system used in the prior art, except that the throttle manifold 4 for controlled pressure drilling includes a first regulating pipeline 401, a second regulating pipeline 402 and an emergency pipeline 403 arranged in parallel, and the second regulating pipeline 402 can be used as a substitute when the first regulating pipeline 401 is damaged. In the event of an abnormal situation, the manual valve in the emergency pipeline 403 can be opened.

[0033] Example 2

[0034] Embodiment 2 of a deepwater managed pressure drilling zoned well control method can discharge the gas-invaded drilling fluid in the watertight pipe of a managed pressure drilling platform system in embodiment 1, such as Figure 2 The specific steps are as follows:

[0035] Step 1: When the annular space of the riser formed by the pressure-controlled drilling rotary control head and the platform seabed blowout preventer is in a closed state, test the pump pressure value of the circulation passage at different displacements of the drilling booster pump;

[0036] Step 2: Control the pressure at the bottom of the riser to maintain the target pressure and discharge the gas-invaded drilling fluid in the riser annulus; the target pressure is the formation pressure minus the bottom hole pressure, and the bottom hole pressure is the sum of the circulation pressure loss and the static liquid column pressure; the pump pressure value is the circulation pressure loss;

[0037] Step 3: After the wellbore below the subsea blowout preventer is killed and filled with heavy slurry, the volume of heavy slurry required for the riser annulus is calculated, and the heavy slurry pumped by the drilling booster pump is injected into the riser annulus from the bottom of the riser through the booster side pipe;

[0038] Step 4: After confirming that the upper and lower pressures of the subsea blowout preventer are balanced, open the subsea blowout preventer and switch to normal operation.

[0039] The working principle of this embodiment: after closing the subsea blowout preventer, the formation products will no longer enter the riser; according to the U-tube principle, the riser annulus and the riser injection side pipes are used as the two sides of the U-tube. Since the riser is filled with gas-invaded drilling fluid, it is necessary to calculate the riser bottom pressure through one side of the injection side pipe (one side of the injection side pipe is filled with pure drilling fluid, and this pressure is the target pressure, the riser bottom pressure = injection pump circulation riser pressure - injection side pipe circulation pressure loss + injection side pipe drilling fluid static liquid column pressure). In actual field operations, the riser bottom pressure is kept constant by controlling the injection pump riser pressure to be constant (i.e., riser pressure control), and finally the gas-invaded drilling fluid in the riser can be discharged.

[0040] The beneficial effects of this embodiment: by adopting this control method, after closing the seabed blowout preventer, the gas-invaded drilling fluid in the riser can be safely and controllably discharged and replaced with heavy slurry. In this process, the pressure at the bottom of the riser is controlled to maintain pressure balance. When discharging the gas-invaded drilling fluid, no gas will enter the riser again, and the drilling equipment in the well will not be left stationary for a long time.

[0041] Example 3

[0042] Embodiment 3 of a deepwater managed pressure drilling zoned well control method can discharge the gas-invaded drilling fluid in the watertight pipe of a managed pressure drilling platform system in embodiment 1, and the specific steps are as follows:

[0043] Step 1: When the annular space of the watertight pipe formed by the pressure-controlled drilling rotary control head and the platform seabed blowout preventer is in a closed state, the test circulation passage is tested at 1 / 4 to 1 / 3 of the normal displacement of the drilling booster pump during drilling, and the obtained pump pressure value is equal to the circulation pressure loss. In this embodiment, the test displacement adopts the low pump speed test method, and the data of the low pump speed test and the pressure-controlled drilling ground throttling manifold are used to realize the safe and controllable discharge of the gas-invaded drilling fluid in the watertight pipe.

[0044] Step 2: adjust the pressure at the bottom of the riser through the throttle valve on the throttle manifold dedicated to pressure-controlled drilling, so that the pressure at the bottom of the riser is maintained at the target pressure, and discharge the gas-invaded drilling fluid in the annulus of the riser; the target pressure is the formation pressure minus the bottom hole pressure, and the bottom hole pressure is the sum of the circulating pressure loss and the static liquid column pressure; the pump pressure value is the circulating pressure loss;

[0045] Step 3: After the wellbore below the subsea blowout preventer is killed and filled with heavy slurry, the volume of heavy slurry required for the riser annulus is calculated, and the heavy slurry pumped by the drilling booster pump is injected into the riser annulus from the bottom of the riser through the booster side pipe;

[0046] Step 4: After confirming that the upper and lower pressures of the subsea blowout preventer are balanced, open the subsea blowout preventer and switch to normal operation.

[0047] The working principle of this embodiment: after closing the subsea blowout preventer, the formation products will no longer enter the riser; according to the U-tube principle, the riser annulus and the riser injection side pipes are used as the two sides of the U-tube. Since the riser is filled with gas-invaded drilling fluid, it is necessary to calculate the riser bottom pressure through one side of the injection side pipe (one side of the injection side pipe is filled with pure drilling fluid, and this pressure is the target pressure, the riser bottom pressure = injection pump circulation riser pressure - injection side pipe circulation pressure loss + injection side pipe drilling fluid static liquid column pressure). In actual field operations, the riser bottom pressure is kept constant by controlling the injection pump riser pressure to be constant (i.e., riser pressure control), and finally the gas-invaded drilling fluid in the riser can be discharged.

[0048] The beneficial effects of this embodiment are as follows: by adopting this control method, after closing the seabed blowout preventer, the gas-invaded drilling fluid in the riser can be safely and controllably discharged and replaced with heavy slurry. In this process, the pressure at the bottom of the riser is controlled to maintain pressure balance. When discharging the gas-invaded drilling fluid, no gas will enter the riser again, and the drilling equipment in the well will not be left stationary for a long time.

[0049] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A deepwater managed pressure drilling zone well control method, characterized in that: The steps include: Step 1: When the annular space of the riser formed by the pressure-controlled drilling rotary control head and the platform seabed blowout preventer is in a closed state, test the pump pressure value of the circulation passage at different displacements of the drilling booster pump; Step 2: Control the pressure at the bottom of the riser to maintain the target pressure and discharge the gas-invaded drilling fluid in the riser annulus; the target pressure is the formation pressure minus the bottom hole pressure, and the bottom hole pressure is the sum of the circulation pressure loss and the static liquid column pressure; the pump pressure value is the circulation pressure loss; Step 3: Inject heavy slurry into the riser annulus; Step 4: Open the subsea blowout preventer and return to normal operation.

2. A deepwater managed pressure drilling zoned well control method according to claim 1, characterized in that: In step 1, 1 / 4 to 1 / 3 of the normal displacement of the drilling booster pump during drilling is used as the test displacement for testing, and the obtained pump pressure value is equal to the circulating pressure loss.

3. A deepwater managed pressure drilling zoned well control method according to claim 1, characterized in that: The displacement test in step 1 is performed by a low pump speed test.

4. A deepwater managed pressure drilling zoned well control method according to claim 2, characterized in that: In the step 2, the pressure at the bottom of the riser is adjusted by the throttle valve on the throttle manifold dedicated to pressure-controlled drilling, so that the pressure at the bottom of the riser is maintained at the target pressure.

5. A deepwater managed pressure drilling zoned well control method according to claim 1, characterized in that: In step three, the specific process is as follows: after the wellbore below the subsea blowout preventer is killed and filled with heavy slurry, the volume of heavy slurry required for the riser annulus is calculated, and the heavy slurry is injected into the riser annulus through the drilling booster pump.

6. A deepwater managed pressure drilling zoned well control method according to claim 5, characterized in that: In step three, the heavy slurry pumped by the drilling booster pump is injected into the riser annulus from the bottom of the riser through the booster side pipe.

7. A deepwater managed pressure drilling zoned well control method according to claim 1, characterized in that: In step 4, after confirming that the upper and lower pressures of the subsea blowout preventer are balanced, the subsea blowout preventer is opened.

8. A managed pressure drilling platform system, characterized in that: The deepwater controlled pressure drilling zoned well control method for realizing the deepwater controlled pressure drilling described in claims 4-7 comprises a deepwater controlled pressure drilling device and a platform circulation system; the deepwater controlled pressure drilling device comprises a controlled pressure drilling rotary control head (1), a controlled pressure drilling diversion spool (2), a controlled pressure drilling diversion pipeline (3) and a controlled pressure drilling special throttling manifold (4); the platform circulation system comprises a drilling booster pump (5), a watertight riser (6), a booster side pipe (7) and a liquid-gas separator (8); the deepwater controlled pressure drilling device is installed on the watertight riser (6), one end of the drilling rotary control head is connected to the upper section of the watertight riser (6), and the other end is connected to the controlled pressure drilling diversion spool (2), so that The other end of the pressure-controlled drilling diversion spool (2) is connected to the lower section of the watertight riser (6), the pressure-controlled drilling diversion pipeline (3) is connected to the pressure-controlled drilling diversion spool (2), the pressure-controlled drilling special throttling manifold (4) is connected to the pressure-controlled drilling diversion pipeline (3), and the outlet end of the pressure-controlled drilling special throttling manifold (4) is connected to the liquid-gas separator (8); the injection side pipe (7) is installed outside the watertight riser (6) and is connected to the bottom of the watertight riser (6), the bottom of the lower end of the watertight riser (6) is used to connect to the seabed blowout preventer, and the drilling injection pump (5) is connected to the injection side pipe (7) located at the upper end of the watertight riser (6).

9. A managed pressure drilling platform system according to claim 8, characterized in that: The throttle valve (9) for adjusting the pressure is installed on the throttle manifold (4) dedicated for pressure-controlled drilling.

10. A managed pressure drilling platform system according to claim 8, characterized in that: The throttle manifold (4) dedicated to pressure-controlled drilling comprises a first regulating pipeline (401), a second regulating pipeline (402) and an emergency pipeline (403) arranged in parallel, the first regulating pipeline (401), the second regulating pipeline (402) and the emergency pipeline (403) are each provided with two manual valves, and the first regulating pipeline (401) and the second regulating pipeline (402) are also provided with the throttle valve (9).

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