CN116974312B - A method of wellbore pressure control for natural gas hydrate drilling and production - Google Patents

Abstract

The application relates to the field of drilling engineering, and provides a method for controlling the pressure of a drilling shaft by using natural gas hydrate, which comprises the steps of acquiring pressure data of the bottom of the drilling shaft in the drilling shaft, acquiring pressure data of a drill bit by using a drilling machine in the drilling process of the natural gas hydrate, recording the pressure data of the bottom of the drilling shaft as first data, recording the pressure data of the drill bit as second data, and establishing a pressure interaction registration curve based on the first data and the second data. The method can accurately control pressure matching in the drilling and production process, prevent the drilling machine from generating pressure unbalance, establish a pressure interactive registration curve by carrying out data matching on pressure data of the drilling bottom and the drilling bit of the drilling machine, and realize the prediction of pressure change trend through the curve, thereby accurately controlling pressure adjustment in the production operation process, enabling the drilling bit to be always kept in a proper pressure interval, ensuring the service life of the drilling tool, realizing balanced pressure drilling at the same time, and improving the drilling and production efficiency.

Description

A method of wellbore pressure control for natural gas hydrate drilling and production

Technical field

The invention relates to the field of drilling engineering, and in particular to a wellbore pressure control method for natural gas hydrate drilling and production.

Background technique

Natural gas hydrate is a natural gas resource that widely exists in marine sediments. It has high energy density and abundant reserves. It mostly exists in deep sea sediments or terrestrial sediments in extremely low temperature environments. Because natural gas hydrates form under high pressure and It is stable under low temperature conditions and is highly fragile. Therefore, the process of natural gas hydrate extraction needs to consider a variety of factors, including pressure control, temperature management, wellbore stability, etc.

During the drilling process of natural gas hydrate, the pressure control of the drill bit is a key factor affecting the drilling effect. When the pressure at the bottom of the well is higher than the pressure exerted by the drilling rig, the high-pressure formation fluid will erupt from the bottom of the well, forming a blowout phenomenon. When the pressure at the bottom of the well is lower than the drilling rig pressure, it is easy to cause the well wall to be unstable, leading to problems such as wellbore deformation, drilling stuck, and wellbore collapse, seriously affecting the normal progress of drilling and production work.

Traditional pressure control methods mainly rely on adjusting the density and flow rate of drilling fluid, or balancing bottom hole pressure and drilling rig pressure through safety devices such as pressure turbine systems and blowout prevention wellheads. However, most natural gas hydrate drilling and production environments are in complex The geological conditions and the location of hydrates have unpredictable distribution characteristics. In the face of drilling operations in high-pressure and low-temperature environments, traditional pressure control methods are often difficult to achieve precise pressure control. Therefore, a drill bit that can monitor and adjust the drill bit in real time is needed. Precise pressure control method to enhance the pressure calibration performance during natural gas hydrate drilling and production, thereby improving mining efficiency and safety, and adapting to the needs of different geological conditions and drilling and production environments.

Contents of the invention

The purpose of the present invention is to propose a wellbore pressure control method for natural gas hydrate drilling and production to solve one or more technical problems existing in the prior art and at least provide a beneficial choice or create conditions.

The invention provides a wellbore pressure control method for natural gas hydrate drilling and production, which obtains the pressure data of the drilling bottom in the wellbore. During the drilling and production of natural gas hydrate, the pressure data of the drill bit is obtained through the drilling rig. The pressure data of the drilling bottom is recorded as The first data is the pressure data of the drill bit as the second data. Based on the first data and the second data, a pressure interactive registration curve is established. The method described can accurately control the pressure matching during the drilling process and prevent pressure imbalance in the drilling rig. By matching the pressure data at the bottom of the drilling well and the drill bit of the drilling rig, a pressure interactive registration curve is established, and the pressure change trend is predicted through this curve. , thereby accurately controlling the pressure adjustment during the mining operation, so that the drill bit is always maintained in an appropriate pressure range, ensuring the service life of the drilling tool, while achieving balanced pressure drilling and improving drilling efficiency.

In order to achieve the above objects, according to one aspect of the present invention, a method for controlling wellbore pressure in natural gas hydrate drilling and production is provided, which method includes the following steps:

S100, obtain the pressure data of the drilling bottom in the wellbore;

S200, during the drilling and production process of natural gas hydrate, the pressure data of the drill bit is obtained through the drilling rig;

S300, record the pressure data at the bottom of the drilling well as the first data, and record the pressure data at the drill bit as the second data;

S400: Establish a pressure interactive registration curve based on the first data and the second data.

Further, in step S100, the method for obtaining the pressure data of the drilling bottom in the wellbore is: arranging a logging-while-drilling tool in the wellbore, and monitoring the pressure at the bottom of the wellbore in real time through the pressure sensor in the logging-while-drilling tool. , thereby obtaining real-time pressure data at the bottom of the wellbore, which is the local stratum where the drill bit of the drilling rig contacts the bottom of the wellbore; or, obtain real-time pressure data at the bottom of the wellbore through a multi-parameter comprehensive logging system, or, through The pressure while drilling monitoring system obtains real-time pressure data at the bottom of the wellbore;

In any period T, take _Ti as the i-th second in period T, i as the sequence number, Ti as the time, and PA(T _{i )} as the wellbore monitored by the LWD tool at time _Ti The pressure at the bottom of the drilling well, the value range of i is i=1,2,…,N, N is the length of the period T, then PA(T _i )=PA(T ₁ ),PA(T ₂ ),…, PA(T _N ), record PA(T _i ) as the pressure data at the bottom of the wellbore.

Optionally, the model of the logging while drilling tool is SDJWH-3.

Optionally, the LWD instrument is installed on the inner wall of the wellbore, or attached to the drill pipe of the drilling rig.

Further, in step S200, during the drilling and production process of natural gas hydrate, the method of obtaining the pressure data of the drill bit through the drilling rig is specifically: within the period T, obtain the real-time pressure data of the drill bit through the pressure sensor in the drilling rig, and use PB ( T _i ) as the pressure of the drill bit at time T _i , then PB(T _i )=PB(T ₁ ), PB(T ₂ ),…,PB(T _N ), and PB(T _i ) is recorded as the pressure of the drill bit pressure data.

Optionally, the period T is set to any N minutes (length N*60) within 24 hours of a natural day, or the period T is set to any length N*60 during the drilling and production of natural gas hydrates in the wellbore. Period (length in seconds), where N is set to an integer in the interval [30,60].

Further, in step S300, the method of recording the pressure data at the bottom of the drilling well as the first data and recording the pressure data of the drill bit as the second data is specifically: creating a blank set PA[] and a blank set PB[] respectively; Add all the pressure data PA(T ₁ ), PA(T ₂ ),..., PA(T _N ) at the bottom of the drilling well to the set PA[], and add the pressure data PB(T ₁ ), PB(T ₂ ) of the drill bit, ..., PB(T _N ) are all added to the set PB[], then the lengths of the set PA[] and the set PB[] are both N; the set PA[] is recorded as the first data, and the set PB[] is recorded as the second data.

Further, in step S400, based on the first data and the second data, the method for establishing the pressure interactive registration curve is specifically:

S401, use PA(i) as the i-th element in the array PA, use PB(i) as the i-th element in the array PB, i is the sequence number, and the value range of i is i=1,2,…, N, initialize a variable j. The value range of variable j is the same as the value range of sequence number i. PA(j) represents the j-th element in array PA. The value of PA(j) changes with the value of variable j. Variety;

Set one variable R1 and one variable R2 respectively. The initial values of R1 and R2 are both set to 0. Set two blank sets setA{} and setB{} respectively. Traverse variable j starting from j=1 and go to S402;

S402, in the array PB, add all elements whose element values are greater than the value of PA(j) to the set setA{}, and at the same time add all elements whose element values are less than the value of PA(j) to the set setB{}. Let N1 represent the length of the set setA{} (that is, the number of all elements in the set setA{}), let N2 represent the length of the set setB{}, and go to S403;

S403, increase the value of variable R1 by N1, increase the value of variable R2 by N2, and clear the setA{} and setB{} at the same time (that is, delete all elements in these two sets);

If the value of the current variable j is less than N, increase the value of the variable j by 1 and go to S402; if the value of the current variable j is equal to or greater than N, go to S404;

S404, create a blank array cre[] and a blank array ple[] respectively, and compare the value of R1 with the value of R2;

If R1>R2, then in the array PA, select R data of PA(1), PA(2),...,PA(R) and add them to the array cre[], and at the same time select PB(R+ in the array PB 1),PB(R+2),…,PB(N) are added to the array ple[];

If R1<R2, then select R data of PB(1), PB(2),...,PB(R) in the array PB and add it to the array cre[], and select PA(R+1 in the array PA at the same time ),PA(R+2),…,PA(N) are added to the array ple[] and go to S405;

Among them, R=INT(max{R1,R2}/N), max{} means taking the maximum value of the number in {}, and INT() means rounding down the number in ();

S405, use cre(x) to represent the x-th element in the array cre[], x is the serial number, the value range of x is x=1,2,…,S1, S1 is the number of all elements in the array cre[] ; Let ple(y) represent the y-th element in the array ple[], y is a variable, the value range of y is y=1,2,...,S2, S2 is the number of all elements in the array ple[];

A pressure interaction registration curve is established based on the first pressure coefficient and the second pressure coefficient.

Further, the method of establishing a pressure interaction registration curve based on the first pressure coefficient and the second pressure coefficient is specifically:

Record the first pressure coefficient , record the second pressure coefficient/> ; Among them, H0 is the average value of all elements in the array cre[], and H1 is the average value of all elements in the array ple[];

Establish the pressure interaction registration curve P_curve(p):

In the formula, p is the independent variable of the curve, the domain of p is (0,+∞), and K ₀ =R/2.

The beneficial effect of this step is: to achieve balanced pressure drilling, the pressure data of the block in contact with the drill bit is indispensable. When the pressure when the drilling rig drills does not match the bottom hole pressure, it is easy to cause pressure imbalance or drilling failure. , causing the drilling rig load to be abnormal and affecting the normal progress of mining operations. The method in this step samples the real-time pressure data from the bottom of the drilling well and the drill bit of the drilling rig to obtain the first data and the second data, and then selects matches between the two sets of data. The data segment is used to establish a pressure interactive registration curve. The pressure interactive registration curve is adapted to the two situations of sudden pressure increase or sudden drop in the form of a piecewise function. When the change of the curve is relatively steep, it means that at this time The imbalance between drilling pressure and bottom hole pressure is relatively large, so the adjustment range of drill bit pressure also needs to be relatively increased. When the change of the curve is relatively gentle, the adjustment range of drill bit pressure is relatively reduced to achieve pressure balance during drilling. At the same time, the first pressure coefficient and the second pressure coefficient are used to fine-tune the curvature of the pressure interactive registration curve, so that the slope of the curve accurately matches the adjustment range of the drill bit pressure, and then the pressure interactive registration curve is used to effectively achieve pressure balance during drilling. , realize high-precision pressure adjustment of the drill bit based on the real-time curvature of the curve, achieve balanced pressure drilling, minimize the risk of formation fracturing, avoid pressure imbalances during drilling, and fully improve the efficiency of natural gas hydrate drilling operations. , to ensure the safe operation of the drilling rig.

Optionally, in step S400, establishing a pressure interactive registration curve based on the first data and the second data also includes controlling the pressure of the drill bit through the pressure interactive registration curve, specifically: assuming time T ₀ is the natural gas hydration At any time during the drilling process of the material, the pressure sensor of the drill bit at time T ₀ is obtained through the pressure sensor PB(T ₀ ), and the pressure interactive registration curve P_curve(p) is calculated at the point p=PB(T ₀ ) at the slope K ₁ ; let K _p be the pressure value of K ₁ unit;

If PB(T ₀ ) falls within the interval (0,M), then at t0 seconds after time T ₀ , increase the pressure of the drill bit by K _p ; if PB(T ₀ ) falls within the interval (M,+∞) within t0 seconds after time T ₀ , reduce the pressure of the drill bit by K _p ;

Among them, t0 is set to any integer in the interval [5, 30], M=M2/M1.

Preferably, the pressure of the drill bit is controlled through the pressure interactive registration curve. It can also be: assuming time T ₀ is any moment in the drilling and production process of natural gas hydrate, and obtaining the pressure of the drill bit at time T ₀ through the pressure sensor in the drilling rig. The pressure size PB(T ₀ ); if PB(T ₀ ) falls within the interval (0,M), then at t0 seconds after time T ₀ , increase the pressure of the drill bit by 10%; if PB(T ₀ ) If it falls within the interval (M,+∞), then at t0 seconds after time T ₀ , reduce the pressure of the drill bit by 10%.

The beneficial effects of the present invention are: the method can accurately control the pressure matching during the drilling process, prevent pressure imbalance in the drilling rig, and establish a pressure interactive registration curve by matching the pressure data at the bottom of the drilling well and the drill bit of the drilling rig. The curve predicts the pressure change trend, thereby accurately controlling the pressure adjustment during the mining operation, so that the drill bit is always maintained in an appropriate pressure range, ensuring the service life of the drilling tool, while achieving balanced pressure drilling and improving drilling efficiency.

Description of the drawings

The above and other features of the present invention will be more apparent from the detailed description of the embodiments shown in the accompanying drawings. In the drawings of the present invention, the same reference numerals designate the same or similar elements. It will be apparent that the appended drawings in the following description The drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without exerting creative efforts. In the drawings:

Figure 1 shows a flow chart of a wellbore pressure control method for natural gas hydrate drilling and production.

Detailed ways

The following will give a clear and complete description of the concept, specific structure and technical effects of the present invention in conjunction with the embodiments and drawings, so as to fully understand the purpose, solutions and effects of the present invention. It should be noted that, as long as there is no conflict, the embodiments and features in the embodiments of this application can be combined with each other.

In the description of the present invention, several means one or more, plural means two or more, greater than, less than, more than, etc. are understood to exclude the original number, and above, below, within, etc. are understood to include the original number. If there is a description of first and second, it is only for the purpose of distinguishing technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of indicated technical features or implicitly indicating the order of indicated technical features. relation.

Figure 1 shows a flow chart of a wellbore pressure control method for natural gas hydrate drilling and production according to the present invention. The following describes a natural gas hydrate drilling and production wellbore pressure control method according to an embodiment of the present invention in conjunction with Figure 1 .

The present invention proposes a method for controlling pressure in a natural gas hydrate drilling and production wellbore. The method includes the following steps:

S100, obtain the pressure data of the drilling bottom in the wellbore;

S200, during the drilling and production process of natural gas hydrate, the pressure data of the drill bit is obtained through the drilling rig;

S300, record the pressure data at the bottom of the drilling well as the first data, and record the pressure data at the drill bit as the second data;

S400: Establish a pressure interactive registration curve based on the first data and the second data.

Further, in step S100, the method for obtaining the pressure data of the drilling bottom in the wellbore is: arranging a logging-while-drilling tool in the wellbore, and monitoring the pressure at the bottom of the wellbore in real time through the pressure sensor in the logging-while-drilling tool. , thereby obtaining real-time pressure data at the bottom of the wellbore, which is the local stratum where the drill bit of the drilling rig contacts the bottom of the wellbore;

In any period T, take _Ti as the i-th second in period T, i as the sequence number, Ti as the time, and PA(T _{i )} as the wellbore monitored by the LWD tool at time _Ti The pressure at the bottom of the drilling well, the value range of i is i=1,2,…,N, N is the length of the period T, then PA(T _i )=PA(T ₁ ),PA(T ₂ ),…, PA(T _N ), record PA(T _i ) as the pressure data at the bottom of the wellbore.

Further, in step S200, during the drilling and production process of natural gas hydrate, the method of obtaining the pressure data of the drill bit through the drilling rig is specifically: within the period T, obtain the real-time pressure data of the drill bit through the pressure sensor in the drilling rig, and use PB ( T _i ) as the pressure of the drill bit at time T _i , then PB(T _i )=PB(T ₁ ), PB(T ₂ ),…,PB(T _N ), and PB(T _i ) is recorded as the pressure of the drill bit pressure data.

Specifically, the period T is set to any N minutes within 24 hours of a natural day (the period length is N*60, in seconds), where N is set to 30.

Further, in step S300, the method of recording the pressure data at the bottom of the drilling well as the first data and recording the pressure data of the drill bit as the second data is specifically: creating a blank set PA[] and a blank set PB[] respectively; Add all the pressure data PA(T ₁ ), PA(T ₂ ),..., PA(T _N ) at the bottom of the drilling well to the set PA[], and add the pressure data PB(T ₁ ), PB(T ₂ ) of the drill bit, ..., PB(T _N ) are all added to the set PB[], then the lengths of the set PA[] and the set PB[] are both N; the set PA[] is recorded as the first data, and the set PB[] is recorded as the second data.

Further, in step S400, based on the first data and the second data, the method for establishing the pressure interactive registration curve is specifically:

S401, use PA(i) as the i-th element in the array PA, use PB(i) as the i-th element in the array PB, i is the sequence number, and the value range of i is i=1,2,…, N, initialize a variable j. The value range of variable j is the same as the value range of sequence number i. PA(j) represents the j-th element in array PA. The value of PA(j) changes with the value of variable j. Variety;

Set one variable R1 and one variable R2 respectively. The initial values of R1 and R2 are both set to 0. Set two blank sets setA{} and setB{} respectively. Traverse variable j starting from j=1 and go to S402;

S402, in the array PB, add all elements whose element values are greater than the value of PA(j) to the set setA{}, and at the same time add all elements whose element values are less than the value of PA(j) to the set setB{}. Let N1 represent the length of the set setA{} (that is, the number of all elements in the set setA{}), let N2 represent the length of the set setB{}, and go to S403;

S403, increase the value of variable R1 by N1, increase the value of variable R2 by N2, and clear the setA{} and setB{} at the same time (that is, delete all elements in these two sets);

If the value of the current variable j is less than N, increase the value of the variable j by 1 and go to S402; if the value of the current variable j is equal to or greater than N, go to S404;

S404, create a blank array cre[] and a blank array ple[] respectively, and compare the value of R1 with the value of R2;

If R1>R2, then in the array PA, select R data of PA(1), PA(2),...,PA(R) and add them to the array cre[], and at the same time select PB(R+ in the array PB 1),PB(R+2),…,PB(N) are added to the array ple[];

If R1<R2, then select R data of PB(1), PB(2),...,PB(R) in the array PB and add it to the array cre[], and select PA(R+1 in the array PA at the same time ),PA(R+2),…,PA(N) are added to the array ple[] and go to S405;

Among them, R=INT(max{R1,R2}/N), max{} means taking the maximum value of the number in {}, and INT() means rounding down the number in ();

S405, use cre(x) to represent the x-th element in the array cre[], x is the serial number, the value range of x is x=1,2,…,S1, S1 is the number of all elements in the array cre[] ; Let ple(y) represent the y-th element in the array ple[], y is a variable, the value range of y is y=1,2,...,S2, S2 is the number of all elements in the array ple[];

A pressure interaction registration curve is established based on the first pressure coefficient and the second pressure coefficient.

Further, the method of establishing a pressure interaction registration curve based on the first pressure coefficient and the second pressure coefficient is specifically:

Record the first pressure coefficient , record the second pressure coefficient/> ; Among them, H0 is the average value of all elements in the array cre[], and H1 is the average value of all elements in the array ple[];

Establish the pressure interaction registration curve P_curve(p):

In the formula, p is the independent variable of the curve, the domain of p is (0,+∞), and K ₀ =R/2.

Optionally, in step S400, establishing a pressure interactive registration curve based on the first data and the second data also includes controlling the pressure of the drill bit through the pressure interactive registration curve, specifically: assuming time T ₀ is the natural gas hydration At any time during the drilling process of the material, the pressure sensor of the drill bit at time T ₀ is obtained through the pressure sensor PB(T ₀ ), and the pressure interactive registration curve P_curve(p) is calculated at the point p=PB(T ₀ ) at the slope K ₁ ; let K _p be the pressure value of K ₁ unit;

If PB(T ₀ ) falls within the interval (0,M), then at t0 seconds after time T ₀ , increase the pressure of the drill bit by K _p ; if PB(T ₀ ) falls within the interval (M,+∞) within t0 seconds after time T ₀ , reduce the pressure of the drill bit by K _p ;

Among them, t0 is set to 10, M=M2/M1.

Preferably, the pressure of the drill bit is controlled through the pressure interactive registration curve. It can also be: assuming time T ₀ is any moment in the drilling and production process of natural gas hydrate, and obtaining the pressure of the drill bit at time T ₀ through the pressure sensor in the drilling rig. The pressure size PB(T ₀ ); if PB(T ₀ ) falls within the interval (0,M), then at t0 seconds after time T ₀ , increase the pressure of the drill bit by 10%; if PB(T ₀ ) If it falls within the interval (M,+∞), then at t0 seconds after time T ₀ , reduce the pressure of the drill bit by 10%.

The invention provides a wellbore pressure control method for natural gas hydrate drilling and production, which obtains the pressure data of the drilling bottom in the wellbore. During the drilling and production of natural gas hydrate, the pressure data of the drill bit is obtained through the drilling rig. The pressure data of the drilling bottom is recorded as The first data is the pressure data of the drill bit as the second data. Based on the first data and the second data, a pressure interactive registration curve is established. The method described can accurately control the pressure matching during the drilling process and prevent pressure imbalance in the drilling rig. By matching the pressure data at the bottom of the drilling well and the drill bit of the drilling rig, a pressure interactive registration curve is established, and the pressure change trend is predicted through this curve. , thereby accurately controlling the pressure adjustment during the mining operation, so that the drill bit is always maintained in an appropriate pressure range, ensuring the service life of the drilling tool, while achieving balanced pressure drilling and improving drilling efficiency. While the invention has been described in considerable detail and particularly with respect to several of the described embodiments, it is not intended to be limited to any such details or embodiments or to any particular embodiment so as to effectively encompass the intended scope of the invention. In addition, the above description of the present invention is based on embodiments foreseeable by the inventor for the purpose of providing a useful description, and those non-substantive changes to the present invention that are not yet foreseen can still represent equivalent changes of the present invention.

Claims (6)

1. A method for controlling pressure in a drilling and production well bore of natural gas hydrate, comprising the steps of:

s100, acquiring pressure data of the bottom of a well in a shaft;

s200, in the drilling and production process of the natural gas hydrate, pressure data of a drill bit are obtained through a drilling machine;

s300, recording pressure data of the bottom of the well as first data and recording pressure data of the drill bit as second data;

s400, establishing a pressure interaction registration curve based on the first data and the second data;

in step S400, the method for establishing the pressure interaction registration curve based on the first data and the second data specifically includes:

s401, taking PA (i) as the ith element in the set PA [ ], PB (i) as the ith element in the set PB [ ], i as a serial number, the value range of i is i=1, 2, …, N, initializing a variable j, wherein the value range of the variable j is the same as the value range of the serial number i, the jth element in the set PA [ ] is represented by PA (j), and the value of PA (j) changes along with the value change of the variable j;

setting a variable R1 and a variable R2, wherein initial values of R1 and R2 are set to 0, and two blank sets setA { } and setB { } are set respectively, traversing variable j from j=1, and turning to S402;

s402, in the set PB [ ], adding all elements with the element value larger than the value of PA (j) into the set setA { }, adding all elements with the element value smaller than the value of PA (j) into the set setB { }, wherein the length of the set setA { } is represented by N1, the length of the set setB { } is represented by N2, and turning to S403;

s403, increasing the value of the variable R1 by N1, increasing the value of the variable R2 by N2, and simultaneously clearing the set setA { and the set setB { };

if the value of the current variable j is less than N, the value of the variable j is increased by 1, and the process goes to S402; if the value of the current variable j is equal to or greater than N, go to S404;

s404, respectively creating a blank array cre [ ] and a blank array ple [ ], and comparing the value of R1 with the value of R2;

if R1> R2, selecting R data of PA (1), PA (2), … and PA (R) from the set PA [ ], adding the R data into an array cre [ ], and simultaneously selecting PB (R+1), PB (R+2), … and PB (N) from the set PB [ ] and adding the PB (R+2) and PB (N) into an array ple [ ];

if R1< R2, selecting PB (1), PB (2), …, PB (R) in the set PB [ ] and adding the R data into the array cre [ ] and selecting PA (R+1), PA (R+2), … and PA (N) in the set PA [ ] and adding the PA (N) into the array ple [ ] at the same time, and turning to S405;

s405, using cre (x) to represent the xth element in the array cre [ ], wherein x is a serial number, the value range of x is x=1, 2, …, S1, S1 is the number of all elements in the array cre [ ]; the element y in the array ple [ ] is represented by ple (y), y is a variable, the value range of y is y=1, 2, …, S2, S2 is the number of all elements in the array ple [ ];

establishing a pressure interaction registration curve based on the first pressure coefficient and the second pressure coefficient;

the method for establishing the pressure interaction registration curve based on the first pressure coefficient and the second pressure coefficient specifically comprises the following steps:

record the first pressure coefficientNote second pressure coefficient->The method comprises the steps of carrying out a first treatment on the surface of the Wherein H0 is an array cre [ sic ]]Average value of all elements in (1) H1 is array ple [ []Average value of all elements in (a);

establishing a pressure interaction registration curve P_cure (P):

where p is the argument of the curve, the definition field of p is (0, + -infinity), K ₀ =R/2。

2. The method for controlling the pressure of a drilling well bore by using natural gas hydrate according to claim 1, wherein in step S100, the method for acquiring pressure data of the bottom of the drilling well bore in the well bore is as follows: arranging a logging while drilling instrument in a shaft, and monitoring the pressure at the bottom of the well drilling in the shaft in real time through a pressure sensor in the logging while drilling instrument, so as to obtain real-time pressure data at the bottom of the well drilling in the shaft, wherein the bottom of the well drilling, namely a local stratum contacted by a drill bit of a drilling machine and the bottom of the shaft; or, acquiring real-time pressure data of the bottom of the well drilling in the shaft through a multi-parameter comprehensive well logging system, or acquiring real-time pressure data of the bottom of the well drilling in the shaft through a pressure while-drilling monitoring system; PA (T) _i ) Recorded as pressure data at the bottom of the well in the wellbore.

3. A method of controlling wellbore pressure in drilling and production of natural gas hydrates as claimed in claim 2, wherein PA (T _i ) The calculation method of (a) specifically comprises the following steps:

in any period T, with T _i As the ith second in the period T, i is the sequence number, T _i For the time of day, PA (T _i ) At time T as logging while drilling tool _i The monitored pressure of the bottom of the well in the well bore is i=1, 2, …, N, N is the length of the period T, and PA (T _i )=PA(T ₁ ),PA(T ₂ ),…,PA(T _N ) PA (T) _i ) Recorded as pressure data at the bottom of the well in the wellbore.

4. The method for controlling the pressure of a drilling well bore by using a natural gas hydrate according to claim 1, wherein in step S200, the method for obtaining pressure data of a drill bit by using a drilling machine during the drilling process of the natural gas hydrate is specifically as follows: during a period T, real-time pressure data of the drill bit is acquired by a pressure sensor in the drill, at PB (T _i ) As a drill bit at time T _i Pressure of PB (T) _i )=PB(T ₁ ),PB(T ₂ ),…,PB(T _N ) PB (T) _i ) Recorded as pressure data for the drill bit.

5. The method for controlling the pressure of a drilling well bore by using natural gas hydrate according to claim 1, wherein in step S300, the method for recording pressure data of the bottom of the drilling well as first data and recording pressure data of the drill bit as second data specifically comprises: creating a blank set PA respectively]And a blank set PB []The method comprises the steps of carrying out a first treatment on the surface of the Pressure data PA (T ₁ ),PA(T ₂ ),…,PA(T _N ) All added to the set PA]Pressure data PB (T ₁ ),PB(T ₂ ),…,PB(T _N ) All added to set PB]In (C), then, the set PA []Sum set PB []Is N in length; memory collection PA]For the first data, record set PB [ []Is the second data.

6. The method for controlling the pressure of a drilling and production well bore of a natural gas hydrate according to claim 1, wherein R data are calculated by the following method: r=int (max { R1, R2 }/N), max { } denotes that the number within { } is maximized, INT () denotes that the number within () is rounded down.