Drilling engineering geological risk quantification method

Abstract

The invention relates to the technical field of drilling engineering, in particular to a drilling engineering geological risk quantitative method which comprises the following steps: S1, establishing a drilling engineering geological risk quantitative calculation model; s2, geological factors are identified; s3, calculating a drilling geological risk grade value; and S4, risk classification prevention is carried out according to the drilling geological risk grade value. According to the method, the drilling risk geological factors of the target stratum can be identified, the risk level can be quantitatively calculated, corresponding prevention and control measures are taken according to the risk level, the pertinence is high, the risk prevention and control cost is reduced, and the drilling efficiency is improved.

Description

Technical Field

[0001] The invention relates to the technical field of drilling engineering, and is a drilling engineering geological risk quantitative method. Background Art

[0002] With the deepening of oil exploration and development, the exploration and development targets have gradually shifted to deep and unconventional oil and gas reservoirs. However, deep exploration and development involves drilling and uncovering many strata with complex structures. Unconventional oil and gas reservoirs use high-angle and horizontal wells for production and exploitation. There are many geological factors in drilling geological risks, and it is difficult to drill wells quickly and safely with high quality, reduce costs and increase efficiency. Accurate drilling engineering geological risk level data is required.

[0003] Drilling geological risk is the main factor leading to underground complexity. Dealing with underground complex factors requires a lot of time and money. Accurately calculating the geological risk level and taking corresponding measures based on the level can reduce the probability of risk and achieve the goal of reducing costs and increasing efficiency.

[0004] Traditional geological risk prevention measures use regional and neighboring well data, statistical analysis, and qualitative judgment of geological risks, which are then cited in drilling geological design or engineering design, but have poor prompt and warning effects.

[0005] Currently, there is no quantitative calculation method for drilling geological risks. In drilling geology and engineering design, statistical areas, drilling data, and geological risks are qualitatively identified, and risk prevention and control measures are taken passively. However, the measures are often inappropriate and the prevention and control effects are poor. Summary of the invention

[0006] The present invention provides a drilling engineering geological risk quantification method, which overcomes the shortcomings of the above-mentioned prior art and can effectively solve the problems of qualitatively identifying geological risks, passively taking risk prevention and control measures, and poor prevention and control effects.

[0007] One of the technical solutions of the present invention is achieved by the following measures: A drilling engineering geological risk quantification method comprises the following steps:

[0008] Step S1, establishing a quantitative calculation model for drilling engineering geological risks;

[0009] Step S2, identifying geological factors;

[0010] Step S3, calculating the drilling geological risk level value;

[0011] Step S4: classify and prevent risks according to the drilling geological risk level value.

[0012] The following is a further optimization and / or improvement of one of the above-mentioned technical solutions:

[0013] The above step S1 may specifically include the following steps:

[0014] S1.1. Identify the geological risks of drilling engineering;

[0015] S1.2, introduce geological risk factors;

[0016] S1.3, introduce drilling geological risks;

[0017] S1.4. Calculate the drilling geological risk level value. The calculation model is:

[0018]

[0019] Where R is the risk level score; d is the drilling risk name; F i is the geological factor evaluation value; Fmin i is the lower limit of geological factor evaluation value; Fwin i W is the geological factor window length; i is the weight of geological factors; i is the i-th geological factor; n is the number of geological factors.

[0020] In the above step S2, the drilling risk can be identified according to the drilling technology and geological characteristics, and then the geological elements can be evaluated using the logging curve to calculate the risk level.

[0021] The above step S3 may specifically include the following steps:

[0022] S3.1. Determine the number of geological elements of drilling geological risk based on the relationship table between drilling geological risk and geological elements of drilling risk and the geological element evaluation results;

[0023] S3.2. Determine the number of geological elements of drilling geological risk based on the relationship table between drilling geological risk and geological elements of drilling risk and the geological element evaluation results;

[0024] S3.3. Determine the lower limit of geological factor evaluation value, geological factor window length, and geological factor weight for each geological element;

[0025] S3.4. Calculate the risk level value for each drilling risk.

[0026] When conducting risk classification and prevention, geological risks can be divided into three levels: low, medium and high according to the drilling risk grade score.

[0027] When the risk level value is less than 10, it is a general risk and pre-drilling risk assessment is required; when the risk level value is greater than 10 and less than 20, it is a moderate risk and while-drilling risk monitoring is required; when the risk level value is greater than 20, it is a high risk and while-drilling risk control is required.

[0028] The block geology, drilling, logging, mud logging and logging and drilling data can be used to construct a geological risk level calculation model, establish the relationship between geological risk and geological elements and classification standards, calculate risks using block, adjacent well and drilling data, and divide geological risk levels.

[0029] The second technical solution of the present invention is achieved through the following measures: a terminal device includes a memory and a processor, the memory stores a program that can be run on the processor, and the processor implements the above-mentioned drilling engineering geological risk quantification method when executing the program.

[0030] The third technical solution of the present invention is achieved through the following measures: a storage medium, which stores one or more programs, and the one or more programs can be executed by one or more processors to implement the above-mentioned drilling engineering geological risk quantification method.

[0031] The purpose of the present invention is to construct a quantitative calculation model for drilling geological risk, identify geological factors of drilling risk, quantitatively calculate the risk level value, determine the risk level, take corresponding measures, prevent and control drilling risks, reduce drilling costs, improve drilling timeliness, and apply it to drilling projects for exploration and development of unconventional and ultra-deep oil and gas reservoirs. In the study of geological risk identification of complex and ultra-deep wells in the southern edge of the Junggar Basin, a set of risk identification methods and geological risk level calculation models based on logging, logging, and drilling were formed, which can be extended to all drilling engineering constructions, and can accurately calculate the geological risk level value and be applied to geological risk identification. The present invention establishes a quantitative method for drilling engineering geological risk, and applies the drilling engineering geological risk factor identification method to identify the drilling risk geological factors of the target stratum, quantitatively calculate the risk level, take corresponding prevention and control measures according to the risk level, take corresponding prevention and control measures, which are highly targeted, reduce risk prevention and control costs, and improve drilling efficiency. The present invention is applied to the drilling project in the southern edge of the Junggar Basin, and the drilling complexity rate is reduced from 33.6% to 15.1%, with a reduction percentage of 55.1%. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Attached Figure 1 It is a schematic diagram of the drilling geological factors and risk identification process according to an embodiment of the present invention.

[0033] Attached Figure 2 It is a schematic diagram of the drilling engineering geological risk quantification method and application results in the Le Tan 1 well according to an embodiment of the present invention. DETAILED DESCRIPTION

[0034] The present invention is not limited by the following embodiments, and specific implementation methods can be determined based on the technical solution of the present invention and actual conditions.

[0035] In the present invention, for the convenience of description, the description of the relative position relationship of each component is described according to the layout of the drawings in the specification, such as: the position relationship of front, back, up, down, left, right, etc. is determined according to the layout direction of the drawings in the specification.

[0036] The present invention will be further described below in conjunction with embodiments and drawings:

[0037] Embodiment 1: As attached Figure 1 As shown, the drilling engineering geological risk quantitative method includes the following steps:

[0038] Step S1, establishing a quantitative calculation model for drilling engineering geological risks;

[0039] S1.1. Identify geological risks of drilling projects.

[0040] As shown in Table 1, the traditional drilling geological risk identification method is qualitative identification, and the drilling risk prompt and warning function is poor. Figure 2 As shown, the application results of the drilling geological risk identification method of an embodiment of the present invention, which identifies the geological factors of drilling risks, calculates the risk grade value according to the logging values ​​of the geological risk factors, judges the risk level according to the grade value, and takes corresponding prevention and control measures, which is highly targeted, reduces the risk prevention and control costs, and improves drilling efficiency.

[0041] Table 1 Comparison of traditional drilling geological risk identification methods

[0042]

[0043] S1.2. Introduce geological risk factors and geological parameters that induce drilling engineering risks in prospecting wells, including high-steep structures, sensitive formations, abnormal pressures, sensitive fluids, and ultra-high permeability layers. By evaluating geological risk factors, calculate the drilling geological risk level score, identify the degree of drilling risk, optimize drilling fluids, wellbore structures, and drilling procedures, avoid the occurrence of drilling engineering geological risk winds, or reduce the intensity of drilling engineering geological risk.

[0044] S1.3, introduce drilling geological risks; among them, drilling engineering risks directly related to geological elements include well wall collapse, rupture and shrinkage; drilling fluid gushing, leakage and denaturation; hydrogen sulfide poisoning, high-pressure blowout and gas explosion risks that may occur at the well site. By identifying drilling geological risks, optimizing drilling fluid, wellbore structure and drilling procedures, avoid the occurrence of drilling engineering geological risks or reduce the intensity of drilling engineering geological risks.

[0045] S1.4. Calculate the drilling geological risk level value. The calculation model is:

[0046]

[0047] Where R is the risk level score; d is the drilling risk name; F i is the geological factor evaluation value; Fmin i is the lower limit of geological factor evaluation value; Fwin i W is the geological factor window length; i is the weight of geological factors; i is the i-th geological factor; n is the number of geological factors.

[0048] Step S2, identifying geological factors;

[0049] Drilling geological risk is the risk of drilling geological elements that may induce certain drilling risks. There is a certain relationship between the two. The relationship between drilling geological risk and drilling risk geological elements is shown in Table 2. According to the drilling process and geological characteristics, the drilling risk is identified, and then the logging curve is used to evaluate the geological elements, and the risk level is calculated using formula (1).

[0050] Table 2 Relationship between drilling geological risk and drilling risk geological factors

[0051]

[0052] Step S3, calculating the drilling geological risk level value, specifically includes the following steps:

[0053] S3.1. Determine the number of geological elements of drilling geological risk based on the relationship table between drilling geological risk and geological elements of drilling risk and the geological element evaluation results;

[0054] S3.2. Determine the number n of geological elements of drilling geological risk based on the relationship table between drilling geological risk and geological elements of drilling risk and the geological element evaluation results;

[0055] S3.3. Determine the lower limit of geological factor evaluation value, geological factor window length, and geological factor weight for each (i) geological element;

[0056] S3.4. Calculate the risk level value R for each drilling risk d.

[0057] Step S4: classify and prevent risks according to the drilling geological risk level value.

[0058] When classifying and preventing risks, geological risks are divided into three levels: low, medium and high according to the drilling risk level score. The classification criteria are shown in Table 3. Specifically, when the risk level value is less than 10, it is a general risk and requires pre-drilling risk assessment; when the risk level value is greater than 10 and less than 20, it is a moderate risk and requires risk monitoring while drilling; when the risk level value is greater than 20, it is a high risk and requires risk control while drilling.

[0059] Table 3 Drilling geological risk classification standard

[0060] The embodiments of the present invention make full use of block geology, drilling, logging, mud logging and mud logging and drilling data while drilling, construct a geological risk level calculation model, establish the relationship between geological risk and geological elements and classification standards, use block, adjacent well and drilling data to calculate risks, divide geological risk levels, and use them for drilling geology and engineering design to prompt and warn of drilling geological risks and guide the prevention and control of drilling geological risks.

[0061] The purpose of the embodiment of the present invention is to construct a quantitative calculation model for drilling geological risk, identify geological factors of drilling risk, quantitatively calculate the risk level value, determine the risk level, take corresponding measures, prevent and control drilling risks, reduce drilling costs, improve drilling timeliness, and apply it to drilling projects for exploration and development of unconventional and ultra-deep oil and gas reservoirs. In the study of geological risk identification of complex and ultra-deep wells in the southern margin of the Junggar Basin, a set of risk identification methods and geological risk level calculation models based on logging, logging, and drilling were formed, which can be extended to all drilling engineering constructions, and can accurately calculate the geological risk level value and apply it to geological risk identification. Specifically, the embodiment of the present invention was applied to 8 deep wells over 6000m in the southern margin of the Junggar Basin, and the drilling complexity rate was reduced by 55.1%. The embodiment of the present invention established a quantitative method for drilling engineering geological risk, and applied the drilling engineering geological risk factor identification method to identify the drilling risk geological factors of the target stratum, quantitatively calculate the risk level, take corresponding prevention and control measures according to the risk level, take corresponding prevention and control measures, which is highly targeted, reduces the risk prevention and control costs, and improves drilling efficiency. The embodiment of the present invention was applied to a drilling project in the southern margin of the Junggar Basin, and the drilling complexity rate was reduced from 33.6% to 15.1%, with a reduction percentage of 55.1%.

[0062] Example 2: The present invention provides a specific application case of the drilling engineering geological risk quantification method, which is applied to Le Tan 1 well in a certain area, and includes the following steps:

[0063] (1) Select the well logging curve of Le Tan 1 well and the complex well history data of the drilling well, and analyze the drilling risk of the K2d-J3k formation, which is well leakage. The geological factors of well leakage are formation pores, fractures and formation pressure. These three geological factors can be evaluated by AC. When the AC value is large, the well leakage is mainly caused by formation pores. When the AC value is small, there may be fractures or drilling-induced fractures in the formation. Determine the value of the well leakage risk level calculated using the AC curve.

[0064] (2) Calculate the risk level of lost circulation drilling using the following formula:

[0065]

[0066] Among them, R is the risk level score; d is the drilling leakage risk; Fi is the acoustic logging value; Fmin i is the lower limit of the acoustic logging value; Fwin i W is the acoustic window length; i is the acoustic wave weight 1; i is the first geological factor; n is 1.

[0067] (3) Using the Rd value, the well leakage risk is classified according to the drilling geological risk level classification standard table. In the embodiment of the present invention, the risk level is medium risk, and drilling monitoring is required.

[0068] The embodiment of the present invention constructs a drilling geological risk level calculation model, identifies drilling risk geological factors, quantitatively calculates the risk level value, determines the risk level, takes corresponding measures, prevents and controls drilling risks, reduces drilling costs, and improves drilling time efficiency. It is applied to unconventional and ultra-deep oil and gas reservoir exploration and development drilling projects, and has achieved good results.

[0069] Embodiment 3: An embodiment of the present invention provides a terminal device, which includes a memory, a processor, a communication interface and a communication bus. The memory stores a program that can be run on the processor. When the processor executes the program, the drilling engineering geological risk quantification method described in the above embodiment is implemented.

[0070] The processor may be a central processing unit, or other general-purpose processors, digital signal processors, application-specific integrated circuits, field programmable gate arrays or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, or a combination of the above chips.

[0071] The memory, as a non-transitory computer-readable storage medium, can be used to store non-transitory software programs, non-transitory computer executable programs and units, such as the corresponding program units in the above method embodiments of the present invention. The processor executes various functional applications of the processor and works data processing by running the non-transitory software programs, instructions and modules stored in the memory, that is, the drilling engineering geological risk quantification method described in the above embodiment is realized.

[0072] The memory may include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application required by at least one function; the data storage area may store data created by the processor, etc. In addition, the memory may include a high-speed random access memory, and may also include a non-volatile memory, such as at least one disk storage device, a flash memory device, or other non-volatile solid-state storage device. The memory may optionally include a memory remotely arranged relative to the processor, and these remote memories may be connected to the processor via a network. The one or more programs are stored in the memory, and when executed by the processor, the drilling engineering geological risk quantification method described in the above embodiment is executed.

[0073] Embodiment 4: The embodiment of the present invention provides a storage medium for computer-readable storage, wherein the storage medium stores one or more programs, and the one or more programs can be executed by one or more processors to implement a drilling engineering geological risk quantification method as described in any one of the above method embodiments.

[0074] The storage medium may be an internal storage unit of the terminal device, such as a hard disk or memory of the terminal device. The storage medium may also be an external storage device of the terminal device, such as a plug-in hard disk, smart memory card, secure digital card, flash memory card, etc. equipped on the terminal device.

[0075] The above technical features constitute the embodiments of the present invention, which have strong adaptability and implementation effect. Non-essential technical features can be added or reduced according to actual needs to meet the requirements of different situations.

Claims

1. A drilling engineering geological risk quantification method, characterized in that The following steps are involved: Step S1, establishing a quantitative calculation model for drilling engineering geological risks; Step S2, identifying geological factors; Step S3, calculating the drilling geological risk level value; Step S4: classify and prevent risks according to the drilling geological risk level value.

2. The drilling engineering geological risk quantification method according to claim 1 is characterized in that Step S1 specifically includes the following steps: S1.

1. Identify the geological risks of drilling engineering; S1.2, introduce geological risk factors; S1.3, introduce drilling geological risks; S1.

4. Calculate the drilling geological risk level value. The calculation model is: Where R is the risk level score; d is the drilling risk name; F i is the geological factor evaluation value; Fmin i is the lower limit of geological factor evaluation value; Fwin i W is the geological factor window length; i is the weight of geological factors; i is the i-th geological factor; n is the number of geological factors.

3. The drilling engineering geological risk quantification method according to claim 1 or 2, characterized in that In step S2, drilling risks are identified based on drilling technology and geological characteristics, and then the geological elements are evaluated using logging curves to calculate the risk level.

4. The drilling engineering geological risk quantification method according to claim 1 or 2, characterized in that Step S3 specifically includes the following steps: S3.

1. Determine the number of geological elements of drilling geological risk based on the relationship table between drilling geological risk and geological elements of drilling risk and the geological element evaluation results; S3.

2. Determine the number of geological elements of drilling geological risk based on the relationship table between drilling geological risk and geological elements of drilling risk and the geological element evaluation results; S3.

3. Determine the lower limit of geological factor evaluation value, geological factor window length, and geological factor weight for each geological element; S3.

4. Calculate the risk level value for each drilling risk.

5. The drilling engineering geological risk quantification method according to claim 3 is characterized in that Step S3 specifically includes the following steps: S3.

1. Determine the number of geological elements of drilling geological risk based on the relationship table between drilling geological risk and geological elements of drilling risk and the geological element evaluation results; S3.

2. Determine the number of geological elements of drilling geological risk based on the relationship table between drilling geological risk and geological elements of drilling risk and the geological element evaluation results; S3.

3. Determine the lower limit of geological factor evaluation value, geological factor window length, and geological factor weight for each geological element; S3.

4. Calculate the risk level value for each drilling risk.

6. The drilling engineering geological risk quantification method according to claim 1, 2 or 5, characterized in that When conducting risk classification and prevention, geological risks are divided into three levels: low, medium and high according to the drilling risk grade score.

7. The drilling engineering geological risk quantification method according to claim 6 is characterized in that When the risk level value is less than 10, it is a general risk and pre-drilling risk assessment is required; when the risk level value is greater than 10 and less than 20, it is a moderate risk and while-drilling risk monitoring is required; when the risk level value is greater than 20, it is a high risk and while-drilling risk control is required.

8. The drilling engineering geological risk quantification method according to claim 1, 2, 5 or 7, characterized in that Using block geology, drilling, logging, mud logging and logging while drilling, a geological risk level calculation model is constructed, the relationship between geological risk and geological elements and classification standards are established, and the risk is calculated using block, adjacent well and drilling data to divide the geological risk level.

9. A terminal device, comprising a memory and a processor, wherein the memory stores a program that can be run on the processor, characterized in that: When the processor executes the program, the drilling engineering geological risk quantification method as described in any one of claims 1 to 8 is implemented.

10. A storage medium, characterized in that: The storage medium stores one or more programs, and the one or more programs can be executed by one or more processors to implement the drilling engineering geological risk quantification method as described in any one of claims 1 to 8.

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