Deepwater managed pressure drilling zonal well control method and drilling platform system thereof

Abstract

The present application relates to a kind of deep water pressure control drilling partition well control control method, comprising: in the annular space of riser formed by pressure control drilling rotary control head and platform subsea blowout preventer is in the state of up and down airtight, test circulating passage under the different displacement of drilling injection pump Pump pressure value;Control the pressure at the bottom of riser keeps as target pressure and discharges the gas invasion drilling fluid in the annulus of riser;Target pressure is formation pressure minus bottom hole pressure, bottom hole pressure is the sum of circulating pressure consumption and static column pressure;With the pump pressure value as the circulating pressure consumption;Heavy slurry is injected into the annulus of riser;Open subsea blowout preventer, turn into normal operation.It also includes a kind of pressure control drilling platform system.Adopt the control method, when discharging gas invasion drilling fluid, gas will not enter riser again, and will not cause the drilling tool in well to be in stillness for a long time.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of subsea drilling, and more particularly to a deepwater managed pressure drilling zoned well control method and a drilling platform system thereof. BACKGROUND

[0002] At present, the domestic deepwater managed pressure drilling technology and equipment research and development are in the initial stage, and the exploration and development of deepwater deep oil and gas resources are faced with many challenges such as high temperature and high pressure, narrow safety density window and the like. The blowout preventer group of deepwater drilling is installed on the seabed, and the blowout preventer group and the deepwater drilling platform are connected through a riser and a drilling fluid circulation passage is established. If the conventional deepwater drilling operation encounters gas invasion, it is difficult to discover the gas invasion in time by using conventional monitoring means. When the monitoring equipment discovers the gas invasion, the gas may have entered the riser. In order to safely and effectively control the downhole condition, the drilling platform will close the seabed blowout preventer group and perform well control operation, and the gas in the riser will further slip and expand in the riser, and the circulation passage of the deepwater drilling platform diverter and the liquid-gas separator cannot control the backflow speed, which may seriously cause the gas in the riser to expand and cause damage to the ground equipment and personnel.

[0003] A method for processing gas invasion in a riser is disclosed in the prior art, which provides an improved way of controlling gas expansion in a marine riser, and further provides an improved method and device for restoring the hydrostatic pressure control of the riser after the gas invades the riser. However, the scheme has the following disadvantages:

[0004] (1) The gas invasion drilling fluid in the riser is guided to the diverter and the liquid-gas separator of the platform through the riser gas treatment manifold. The diverter is an annular sealing device, which is usually used in a low pressure system (200psi-500psi working pressure); in addition, after the gas invasion is monitored and discovered, the closing time of the diverter is 30-45s, and during this time, gas still enters the riser, which increases the gas treatment amount and processing difficulty.

[0005] (2) The riser control device is improved, and an annular blowout preventer is installed below the riser expansion joint. When the annular blowout preventer seals the drill string-riser annulus, the drill string cannot rotate and move up and down, which causes the downhole drilling tool to be stationary for a long time, which easily induces complex downhole conditions.

[0006] (3) When processing the gas invasion in the riser and the gas invasion in the wellbore below the seabed blowout preventer, the choke manifold of the platform is used, so that the gas invasion problems of the above two cases cannot be processed at the same time. SUMMARY

[0007] In order to overcome the problems of large processing difficulty and easy occurrence of other conditions in the above-mentioned prior art, the present application provides a deepwater managed pressure drilling zoned well control method, which realizes safe and controllable exclusion of the gas in the riser.

[0008] To solve the above technical problems, the technical scheme adopted by the present application is as follows: a deep water managed pressure drilling partition well control method, comprising the following steps:

[0009] Step one: test the pump pressure value of the circulating passage under different discharge of the drilling injection pump when the annular space of the riser formed by the managed pressure drilling rotary control head and the platform seabed blowout preventer is in the state of upper and lower airtightness;

[0010] Step two: control the pressure at the bottom of the riser to keep the target pressure and discharge the gas invasion drilling fluid in the annular space 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 column pressure; the pump pressure value is the circulating pressure loss;

[0011] Step three: inject heavy slurry into the annular space of the riser;

[0012] Step four: open the seabed blowout preventer and turn to normal operation.

[0013] In the above technical scheme, after the seabed blowout preventer is closed, the formation product will not enter the riser; according to the U-shaped pipe principle, the annular space of the riser and the injection side pipe of the riser are used as the two sides of the U-shaped pipe, and since the gas invasion drilling fluid is in the riser, the pressure at the bottom of the riser needs to be calculated through the injection side pipe (the injection side pipe is filled with pure drilling fluid, and the pressure is the target pressure, the pressure at the bottom of the riser = the circulating standpipe pressure of the injection pump - the circulating pressure loss of the injection side pipe + the static column pressure of the drilling fluid of the injection side pipe), and in the actual field operation, the pressure at the bottom of the riser is kept constant by controlling the circulating standpipe pressure of the injection pump (i.e. standpipe pressure control), and finally the gas invasion drilling fluid in the riser can be discharged.

[0014] Preferably, in step one, 1 / 4-1 / 3 of the normal discharge of the drilling injection pump in the drilling process is used as the test discharge for testing, and the obtained pump pressure value is equal to the circulating pressure loss. The low pump speed test data and the managed pressure drilling surface choke manifold are used to realize the safe and controllable discharge of the gas invasion drilling fluid in the riser with the bottom pressure of the riser as the target value.

[0015] Preferably, the test discharge in step one is in the form of low pump speed test.

[0016] Preferably, in step two, the pressure at the bottom of the riser is adjusted by the choke valve on the managed pressure drilling special choke manifold, so that the pressure at the bottom of the riser keeps the target pressure.

[0017] Preferably, in step three, the specific process is as follows: after killing and filling the wellbore below the subsea blowout preventer 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 injection pump.

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

[0019] Preferably, in step four, after confirming that the pressure above and below the subsea blowout preventer is balanced, the subsea blowout preventer is opened.

[0020] The application also provides a managed pressure drilling platform system for implementing the above-mentioned deepwater managed pressure drilling zonal well control method, comprising a deepwater managed pressure drilling device and a platform circulation system; the deepwater managed pressure drilling device comprises a managed pressure drilling rotary control head, a managed pressure drilling flow distribution cross, a managed pressure drilling flow guide pipe line and a managed pressure drilling dedicated choke manifold; the platform circulation system comprises a drilling injection pump, a riser, an injection side pipe and a liquid-gas separator; the deepwater managed pressure drilling device is installed on the riser, one end of the drilling rotary control head is connected to an upper section of the riser, the other end is connected to the managed pressure drilling flow distribution cross, the other end of the managed pressure drilling flow distribution cross is connected to a lower section of the riser, the managed pressure drilling flow guide pipe line is in communication with the managed pressure drilling flow distribution cross, the managed pressure drilling dedicated choke manifold is in communication with the managed pressure drilling flow guide pipe line, and the outlet end of the managed pressure drilling dedicated choke manifold is in communication with the liquid-gas separator; the injection side pipe is installed outside the riser and is in communication with the bottom of the riser, the bottom of the lower end of the riser is used for connecting to the subsea blowout preventer, and the drilling injection pump is in communication with the injection side pipe located at the upper end of the riser.

[0021] Further, a choke valve for adjusting pressure is installed on the managed pressure drilling dedicated choke manifold.

[0022] Further, the managed pressure drilling dedicated choke manifold comprises a first adjustment pipe line, a second adjustment pipe line and an emergency pipe line arranged in parallel, the first adjustment pipe line, the second adjustment pipe line and the emergency pipe line are each provided with two manual valves, and the first adjustment pipe line and the second adjustment pipe line are further provided with the choke valve.

[0023] Compared with the prior art, the application has the following beneficial effects: by using the control method, the gas-cut drilling fluid in the riser can be safely and controllably discharged and replaced with heavy slurry after the subsea blowout preventer is closed, in the process, by controlling the pressure at the bottom of the riser, the balance of the pressure is maintained, the gas-cut drilling fluid is discharged without gas entering the riser again, and the drilling tools in the well are not kept still for a long time. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1is a structural schematic view of a pressure control drilling platform system of the present application;

[0025] Figure 2 is a flow chart of a deepwater pressure control drilling partition well control method of the present application. DETAILED DESCRIPTION

[0026] The drawings are only used for illustrative description, and should not be understood as limiting the present patent; in order to better illustrate the present embodiment, some components in the drawings may be omitted, enlarged or reduced, and do not represent the actual product size; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted. The positional relationship described in the drawings is only used for illustrative description, and should not be understood as limiting the present patent.

[0027] The same or similar reference numerals in the drawings of the embodiments of the present application correspond to the same or similar components; in the description of the present application, it should be understood that if the terms "upper", "lower", "left", "right", "long" and "short" indicate the orientation or positional relationship shown in the drawings, they are only used for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore the terms describing the positional relationship in the drawings are only used for illustrative description, and should not be understood as limiting the present patent, and for those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0028] The technical solutions of the present application will be further described below through specific embodiments, and in conjunction with the drawings:

[0029] Embodiment 1

[0030] As Figure 1An embodiment of a managed pressure drilling platform system is shown, which comprises a deepwater managed pressure drilling device and a platform circulation system; the deepwater managed pressure drilling device comprises a managed pressure drilling rotary control head 1, a managed pressure drilling diverter cross 2, a managed pressure drilling flow guide line 3 and a managed pressure drilling dedicated choke manifold 4; the platform circulation system comprises a drilling booster pump 5, a riser 6, an injection side pipe 7 and a liquid-gas separator 8; the deepwater managed pressure drilling device is installed on the riser 6, one end of the drilling rotary control head is connected with an upper section of the riser 6, the other end is connected with the managed pressure drilling diverter cross 2, the other end of the managed pressure drilling diverter cross 2 is connected with a lower section of the riser 6, the managed pressure drilling flow guide line 3 is communicated with the managed pressure drilling diverter cross 2, the managed pressure drilling dedicated choke manifold 4 is communicated with the managed pressure drilling flow guide line 3, and an outlet end of the managed pressure drilling dedicated choke manifold 4 is communicated with the liquid-gas separator 8; the injection side pipe 7 is installed outside the riser 6 and communicated to the bottom of the riser 6, the bottom of the lower end of the riser 6 is used for being connected with a subsea blowout preventer, and the drilling booster pump 5 is communicated with the injection side pipe 7 located at the upper end of the riser 6.

[0031] In the embodiment, the managed pressure drilling dedicated choke manifold 4 comprises a first adjusting pipeline 401, a second adjusting pipeline 402 and an emergency pipeline 403 arranged in parallel, the first adjusting pipeline 401, the second adjusting pipeline 402 and the emergency pipeline 403 are each provided with two manual valves, and the first adjusting pipeline 401 and the second adjusting pipeline 402 are further provided with the choke valve 9. The managed pressure drilling dedicated choke manifold 4 is provided with the choke valve 9 for adjusting pressure.

[0032] The managed pressure drilling platform system of the embodiment is consistent with the managed pressure drilling platform system used in the prior art, and the difference lies in that the managed pressure drilling dedicated choke manifold 4 comprises a first adjusting pipeline 401, a second adjusting pipeline 402 and an emergency pipeline 403 arranged in parallel, and the second adjusting pipeline 402 can replace the first adjusting pipeline 401 in case of damage. In case of abnormal situation, the manual valve in the emergency pipeline 403 can be opened.

[0033] Embodiment 2

[0034] Embodiment 2 of a deepwater managed pressure drilling zoned well control method can discharge the gas invasion drilling fluid in the riser of the managed pressure drilling platform system in embodiment 1, as shown in the following specific steps: Figure 2 The specific steps are as follows:

[0035] Step one: test the pump pressure value of the circulation passage under different discharge amounts of the drilling booster pump in the case that the annular space of the riser formed by the managed pressure drilling rotary control head and the platform subsea blowout preventer is in an airtight state.

[0036] Step two: the pressure at the bottom of the riser is kept as a target pressure and the gas invasion drilling fluid in the annulus of the riser is discharged; 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 column pressure; the pump pressure value is the circulating pressure loss;

[0037] Step three: after the wellbore below the subsea blowout preventer is filled with heavy slurry, the volume of heavy slurry required in the riser annulus is calculated, and the heavy slurry extracted by the drilling injection pump is injected into the riser annulus through the injection side pipe at the bottom of the riser.

[0038] Step four: after confirming that the pressure above and below the subsea blowout preventer is balanced, the subsea blowout preventer is opened and normal operation is resumed.

[0039] The working principle of the embodiment is: after the subsea blowout preventer is closed, the formation product will not enter the riser; according to the U-shaped tube principle, the injection side pipe of the riser and the riser annulus are used as the two sides of the U-shaped tube, and since the gas invasion drilling fluid is in the riser, the pressure at the bottom of the riser needs to be calculated through the injection side pipe (the injection side pipe is filled with pure drilling fluid, and the pressure is the target pressure, the pressure at the bottom of the riser = the circulating standpipe pressure of the injection pump - the circulating pressure loss of the injection side pipe + the static column pressure of the drilling fluid of the injection side pipe), and in actual field operation, the pressure at the bottom of the riser is kept constant by controlling the circulating standpipe pressure of the injection pump (i.e. standpipe pressure control), and finally the gas invasion drilling fluid in the riser can be discharged.

[0040] The beneficial effects of the embodiment are: by using the control method, the gas invasion drilling fluid in the riser can be safely and controllably discharged and replaced with heavy slurry after the subsea blowout preventer is closed, and during this process, the pressure balance is maintained by controlling the pressure at the bottom of the riser, so that the gas invasion drilling fluid will not re-enter the riser and the drilling tools in the well will not be in a static state for a long time.

[0041] Embodiment 3

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

[0043] Step one: when the annular space of the riser formed by the managed pressure drilling rotary control head and the platform subsea blowout preventer is in a closed state, test the 1 / 4-1 / 3 of the normal discharge of the circulating path during the drilling process as the test discharge, and the obtained pump pressure value is equal to the circulating pressure loss. In this embodiment, the test discharge is tested by low pump speed, and the data of the low pump speed test and the managed pressure drilling surface choke manifold are used to safely and controllably discharge the gas invasion drilling fluid in the riser.

[0044] Step two: the pressure at the bottom of the riser is kept as a target pressure by adjusting the throttle valve on the throttle manifold for controlled pressure drilling, and the gas invasion drilling fluid in the annulus of the riser is discharged; 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 column pressure; the pump pressure value is the circulating pressure loss;

[0045] Step three: after killing and filling the heavy slurry in the wellbore below the subsea blowout preventer, the volume of the heavy slurry required in the annulus of the riser is calculated, and the heavy slurry pumped by the drilling injection pump is injected into the annulus of the riser from the bottom of the riser through the injection side pipe;

[0046] Step four: after confirming that the pressure above and below the subsea blowout preventer is balanced, the subsea blowout preventer is opened, and normal operation is resumed.

[0047] The working principle of the embodiment is as follows: after the subsea blowout preventer is closed, the formation product will not enter the riser; according to the U-shaped tube principle, the injection side pipe of the riser is used as the U-shaped tube, and the annulus of the riser is used as the other side of the U-shaped tube, and since the gas invasion drilling fluid is in the riser, the pressure at the bottom of the riser needs to be calculated through the injection side pipe (the injection side pipe is filled with pure drilling fluid, and the pressure is the target pressure, and the pressure at the bottom of the riser = the circulating standpipe pressure of the injection pump - the circulating pressure loss of the injection side pipe + the static column pressure of the drilling fluid of the injection side pipe), and in actual field operation, the pressure at the bottom of the riser is kept constant by controlling the circulating standpipe pressure of the injection pump (i.e. standpipe pressure control), and finally the gas invasion drilling fluid in the riser can be discharged.

[0048] The beneficial effects of the embodiment are as follows: by using the control method, the gas invasion drilling fluid in the riser can be safely and controllably discharged and replaced with heavy slurry after the subsea blowout preventer is closed, and in this process, the pressure balance is maintained by controlling the pressure at the bottom of the riser, so that the gas will not enter the riser again when the gas invasion drilling fluid is discharged, and the drilling tools in the well will not be in a static state for a long time.

[0049] Obviously, the above embodiments of the application are only examples for clearly illustrating the application, and are not intended to limit the implementation modes of the application. Based on the above description, other different forms of changes or modifications can be made by those skilled in the art. Here, all the implementation modes are not enumerated, and any modification, equivalent replacement and improvement made within the spirit and principle of the application should be included in the protection scope of the claims of the application.

Claims

1. A method of deepwater managed pressure drilling zonal well control, the method comprising: The method is realized based on a managed pressure drilling platform system, the managed pressure drilling platform system comprising a deepwater managed pressure drilling device and a platform circulation system; the deepwater managed pressure drilling device comprising a managed pressure drilling rotary control head (1), a managed pressure drilling shunt cross (2), a managed pressure drilling flow guide pipeline (3) and a managed pressure drilling dedicated choke manifold (4); the platform circulation system comprising a drilling and injection boosting pump (5), a riser (6), an injection boosting side pipe (7) and a liquid-gas separator (8); the deepwater managed pressure drilling device is installed on the riser (6), one end of the drilling rotary control head is connected with an upper section of the riser (6), the other end is connected with the managed pressure drilling shunt cross (2), the other end of the managed pressure drilling shunt cross (2) is connected with a lower section of the riser (6), the managed pressure drilling flow guide pipeline (3) is communicated with the managed pressure drilling shunt cross (2), the managed pressure drilling dedicated choke manifold (4) is communicated with the managed pressure drilling flow guide pipeline (3), and an outlet end of the managed pressure drilling dedicated choke manifold (4) is communicated with the liquid-gas separator (8); the injection boosting side pipe (7) is installed outside the riser (6) and communicated to the bottom of the riser (6), the bottom of the lower end of the riser (6) is used for being connected with a subsea blowout preventer, and the drilling and injection boosting pump (5) is communicated with the injection boosting side pipe (7) located at the upper end of the riser (6); The method comprises the following steps: Step one: under the condition that the annular space of the riser formed by the managed pressure drilling rotary control head and the subsea blowout preventer is in an upper-lower airtight state, test the pump pressure value of the circulation passage under different discharge capacities of the drilling and injection boosting pump; Step two: control the pressure at the bottom of the riser to keep the target pressure and discharge the gas invasion drilling fluid in the annular space 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 circulation pressure loss and the static liquid column pressure; the pump pressure value is the circulation pressure loss; Step three: inject heavy slurry into the riser annulus; Step four: open the subsea blowout preventer and turn to normal operation.

2. The method of claim 1, wherein, In step one, 1 / 4-1 / 3 of the normal discharge capacity of the drilling and injection boosting pump in the drilling process is taken as the test discharge capacity for testing, and the obtained pump pressure value is equal to the circulation pressure loss.

3. The method of claim 2, wherein, The test discharge capacity in step one adopts the low pump speed test mode.

4. The method of claim 2, wherein A choke valve (9) for adjusting pressure is installed on the managed pressure drilling dedicated choke manifold (4); in step two, the pressure at the bottom of the riser is adjusted through the choke valve on the managed pressure drilling dedicated choke manifold, so that the pressure at the bottom of the riser keeps the target pressure.

5. The method of claim 1, wherein, In step three, the specific process is as follows: after the wellbore below the subsea blowout preventer is filled with heavy slurry after killing, the volume of heavy slurry required by the riser annulus is calculated, and the heavy slurry is injected into the riser annulus through the drilling and injection boosting pump.

6. The method of claim 5, wherein, In step three, the heavy slurry extracted by the drilling and injection boosting pump is injected into the riser annulus from the bottom of the riser through the injection boosting side pipe.

7. The method of claim 1, wherein, In step four, the subsea blowout preventer is opened after it is confirmed that the pressure above and below the subsea blowout preventer reaches balance.

8. The method of claim 4, wherein, The pressure control drilling dedicated choke manifold (4) comprises a first adjusting pipeline (401), a second adjusting pipeline (402) and an emergency pipeline (403) arranged in parallel, the first adjusting pipeline (401), the second adjusting pipeline (402) and the emergency pipeline (403) are provided with two manual valves, and the first adjusting pipeline (401) and the second adjusting pipeline (402) are further provided with the choke valve (9).

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