CN108343424B

CN108343424B - Method and device for determining drilling position

Info

Publication number: CN108343424B
Application number: CN201711370929.3A
Authority: CN
Inventors: 王国亭; 程立华
Original assignee: Petrochina Co Ltd
Current assignee: Petrochina Co Ltd
Priority date: 2017-12-19
Filing date: 2017-12-19
Publication date: 2021-08-03
Anticipated expiration: 2037-12-19
Also published as: CN108343424A

Abstract

The embodiment of the application provides a method and a device for determining a drilling position, wherein the method comprises the following steps: acquiring logging data, core data, gas testing result data and gas layer thicknesses at a plurality of well points in a drilled gas well in a target area; establishing a gas layer near-wellbore area drilling probability set with a plurality of gas layer thicknesses according to the logging data, the core data and the gas testing result data; and determining the drilling position according to the gas layer near-wellbore region drilling probability set with the plurality of gas layer thicknesses and the gas layer thicknesses at a plurality of well points in the drilled gas well. According to the scheme, the drilling probability set of the near-wellbore region of the gas layer with a plurality of gas layer thicknesses with accurate representation effect is established by fully utilizing the data of the drilled gas well, and the drilling position is determined by utilizing the set, so that the technical problem that the drilling position cannot be accurately determined in the existing method is solved, and the technical effect of rapidly and accurately guiding the deployment of a new gas well is achieved.

Description

Method and device for determining drilling position

Technical Field

The application relates to the technical field of gas reservoir development, in particular to a method and a device for determining a drilling position.

Background

In the process of developing gas reservoirs, depletion mining is often used to perform specific gas reservoir exploitation on a gas field. In specific implementation, after a gas well is laid and put into operation, the formation pressure is gradually reduced and the yield of the gas well is gradually reduced along with the exploitation of a gas reservoir. To maintain a long-term steady production of a gas field, it is necessary to drill new gas wells at intervals (e.g., every other year) to compensate for the reduction in production. When deploying a new gas well, it is important to accurately select the deployment location of the new gas well. The position of a new gas well usually requires a certain distance from a drilled gas well, so that the new gas well and the drilled gas well are prevented from being in the same gas layer, the subsequently deployed new gas well is influenced by the drilled gas well, and the gas yield is relatively poor; meanwhile, the distance between the new gas well and the drilled gas well is not required to be too large, so that the phenomenon that other gas layer resources possibly exist in the area between the drilled gas well and the new gas well are missed and lost to cause resource waste can be avoided.

At present, no method specially used for determining the distance between the deployment position of the new gas well and the position of the drilled gas well to determine the deployment position of the new gas well exists. In practice, most of the methods simply design a uniform average well spacing according to some relevant literature data and experience of an implementer, and then search the drilling position of a new gas well in the vicinity of the drilled gas well by taking the average well spacing as a reference. The method does not fully take into account the structural differences of the subsurface gas formations, so that the determined drilling position is not always an ideal deployment position of the new gas well. In summary, the existing method often has a technical problem that the drilling position cannot be accurately determined when the existing method is implemented.

In view of the above problems, no effective solution has been proposed.

Disclosure of Invention

The embodiment of the application provides a method and a device for determining a drilling position, which are used for solving the technical problem that the drilling position cannot be accurately determined in the existing method and achieving the technical effect of quickly and accurately determining the position of a new gas well.

The embodiment of the application provides a method for determining a drilling position, which comprises the following steps:

acquiring logging data, core data, gas testing result data and gas layer thicknesses at a plurality of well points in a drilled gas well in a target area;

establishing a gas layer near-wellbore area drilling probability set with a plurality of gas layer thicknesses according to the logging data, the core data and the gas testing result data;

and determining a drilling position according to the gas layer near-wellbore region drilling probability set of the plurality of gas layer thicknesses and the gas layer thicknesses at a plurality of well points in the drilled gas well.

In one embodiment, the establishing a gas zone near-wellbore region drilling probability set of a plurality of gas zone thicknesses according to the logging data, the core data and the gas test result data comprises:

establishing a thickness distribution probability curve of a target gas layer according to the logging data, the core data and the gas testing result data;

determining the formation environment of a target gas layer according to the core data;

determining the width-thickness ratio of the target gas layer according to the forming environment of the target gas layer;

and establishing a gas layer near-wellbore area drilling probability set with a plurality of gas layer thicknesses according to the width-thickness ratio of the target gas layer and the thickness distribution probability curve of the target gas layer.

In one embodiment, the method further comprises:

acquiring logging data, result explanation data and field measurement data of a drilled gas well in a target area;

correcting the thickness distribution probability curve of the target gas layer according to the logging data, the result interpretation data and the field measurement data to obtain a corrected thickness distribution probability curve of the target gas layer;

correspondingly, according to the width-thickness ratio of the target gas layer and the thickness distribution probability curve of the target gas layer, establishing a gas layer near-wellbore area drilling probability set with a plurality of gas layer thicknesses, including:

and establishing a gas layer near-wellbore area drilling probability set with a plurality of gas layer thicknesses according to the width-thickness ratio of the target gas layer and the corrected thickness distribution probability curve of the target gas layer.

In one embodiment, the determining a drilling location from the set of near-wellbore zone drilling probabilities for the plurality of gas formation thicknesses and the gas formation thicknesses at the plurality of well points in the drilled gas well comprises:

determining a relation curve of the drilling probability and the near-well distance according to the gas layer thicknesses at the plurality of well points and the gas layer near-well zone drilling probability set of the plurality of gas layer thicknesses, wherein the near-well distance is the distance from the drilled gas well;

and determining the drilling position according to the relation curve of the drilling probability and the near-well distance.

In one embodiment, determining a drilling probability versus near-wellbore distance from the set of gas formation near-wellbore zone drilling probabilities for the plurality of gas formation thicknesses and the gas formation thicknesses at the plurality of well points comprises:

selecting a plurality of gas layer near-wellbore zone drilling probability sets meeting the required gas layer thickness from the gas layer near-wellbore zone drilling probability sets of the plurality of gas layer thicknesses according to the gas layer thicknesses at the plurality of well points;

and establishing a relation curve of the drilling probability and the near-well distance according to the set of the drilling probability of the near-well zone of the gas layer with the gas layer thickness meeting the requirements.

In one embodiment, the establishing the drilling probability and near-wellbore distance relationship curve according to the set of drilling probabilities of the gas zone near the well zone of the plurality of satisfactory gas zone thicknesses comprises:

obtaining a plurality of groups of probabilities of drilling the gas layer at the near well distance of the gas layer thickness at a plurality of well points according to the gas layer near well zone drilling probability set of the plurality of gas layer thicknesses meeting the requirements;

and multiplying the probabilities of the gas layer thickness near-well distance drilling encountering gas layers at the well points with the same near-well distance in the probabilities of the gas layer thickness near-well distance drilling encountering gas layers at the plurality of well points respectively to obtain a relation curve of the drilling encountering probability and the near-well distance.

In one embodiment, determining the drilling location based on the drilling encounter probability versus near-wellbore distance comprises:

determining the near well distance with the drilling probability of 0 as a threshold distance according to the relation curve of the drilling probability and the near well distance;

determining a location of the drilled gas well at the threshold distance as the drilling location.

In one embodiment, the target area comprises an area having a low permeability tight sandstone gas reservoir distributed therein.

The embodiment of the present application further provides a device for determining a drilling position, including:

the acquisition module is used for acquiring logging data, core data, gas testing result data and gas bed thicknesses at a plurality of well points in the drilled gas well in a target area;

the establishing module is used for establishing a gas layer near-wellbore area drilling probability set with a plurality of gas layer thicknesses according to the logging data, the core data and the gas testing result data;

and the determining module is used for determining the drilling position according to the gas layer near-wellbore region drilling probability set with the plurality of gas layer thicknesses and the gas layer thicknesses at a plurality of well points in the drilled gas well.

In one embodiment, the establishing module comprises:

the first establishing unit is used for establishing a thickness distribution probability curve of a target gas layer according to the logging data, the rock core data and the gas testing result data;

the first determining unit is used for determining the forming environment of the target gas layer according to the rock core data;

the second determining unit is used for determining the width-thickness ratio of the target gas layer according to the forming environment of the target gas layer;

and the second establishing unit is used for establishing a gas layer near-wellbore area drilling probability set with a plurality of gas layer thicknesses according to the width-thickness ratio of the target gas layer and the thickness distribution probability curve of the target gas layer.

In one embodiment, the determining module comprises:

a third determining unit, configured to determine a relation curve between the drilling probability and a near-well distance according to the gas layer thicknesses at the multiple well points and a gas layer near-well zone drilling probability set of the multiple gas layer thicknesses, where the near-well distance is a distance from a drilled gas well;

and the fourth determining unit is used for determining the drilling position according to the relation curve of the drilling probability and the near-well distance.

In the embodiment of the application, the gas layer near wellbore zone drilling probability set with a plurality of gas layer thicknesses and accurate representation effect is established by fully utilizing the data of the drilled gas well, and the drilling position is determined by utilizing the gas layer near wellbore zone drilling probability set with the plurality of gas layer thicknesses, so that the technical problem that the drilling position cannot be accurately determined in the existing method is solved, and the technical effect of quickly and accurately guiding the deployment of a new gas well is achieved.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below, it is obvious that the drawings in the following description are only some embodiments described in the present application, and for those skilled in the art, other drawings can be obtained according to the drawings without any creative effort.

FIG. 1 is a process flow diagram of a method of determining a drilling location provided in accordance with an embodiment of the present application;

FIG. 2 is a schematic diagram of a probability distribution curve of gas layer thickness of a low-permeability tight gas field obtained by a method for determining a drilling position provided by the embodiment of the application;

FIG. 3 is a schematic cross-sectional view of a binary structural feature of a typical hypotonic-tight gas field reservoir obtained by a method for determining a drilling location according to an embodiment of the present application;

FIG. 4 is a schematic diagram of a low permeability, dense gas field gas layer top-bottom convex space morphology obtained by the method for determining a drilling location provided by the embodiments of the present application;

FIG. 5 is a schematic diagram of a prediction of near-wellbore area spread of a gas reservoir with a well point thickness of 5m obtained by the method for determining the drilling position provided by the embodiment of the application;

FIG. 6 is a diagram for obtaining a prediction intention of a near wellbore area spread of a gas reservoir with a well point thickness of 4m according to a determination method of a drilling position provided by an embodiment of the application;

FIG. 7 is a schematic diagram of a prediction of the near-wellbore area spread of a gas reservoir with a well point thickness of 3m obtained by the method for determining the drilling position provided by the embodiment of the application;

FIG. 8 is a schematic diagram of a method for determining a drilling position to obtain a prediction of a near-wellbore area spread of a gas reservoir with a well point thickness of 2m according to an embodiment of the application;

FIG. 9 is a schematic diagram of a method for determining a drilling position to obtain a prediction of a near-wellbore area spread of a gas reservoir with a well point thickness of 1m according to an embodiment of the application;

FIG. 10 is a schematic diagram of a relation between the simultaneous probability of encountering 5 gas layers and the near-well distance of an S1 well obtained by the method for determining the drilling position according to the embodiment of the application;

FIG. 11 is a block diagram of a device for determining a drilling location provided in accordance with an embodiment of the present application;

FIG. 12 is a schematic representation of a section of a well gas formation of S38-16-3 obtained by applying the method and apparatus for determining a drilling location according to embodiments of the present application in one example scenario;

FIG. 13 is a graphical representation of simultaneous 4 gas zones for a S38-16-3 well obtained using the method and apparatus for determining drilling location according to embodiments of the present application as a function of near-well distance in an exemplary scenario;

FIG. 14 is a plan well map of an S38-16-3 well region obtained using the method and apparatus for determining well location provided by embodiments of the present application in one example scenario.

Detailed Description

In order to make those skilled in the art better understand the technical solutions in the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

Considering that the prior art mostly designs a uniform average well spacing simply according to some relevant literature data and experience of an implementer, the average well spacing is taken as a basis for searching the drilling position of a new gas well in the vicinity of a drilled gas well, and structural differences of underground gas layers are not fully considered, so that the determined drilling position is often not an ideal deployment position of the new gas well. Namely, when the method is implemented, the technical problem that the drilling position cannot be accurately determined often exists. In view of the specific structural differences of the underground gas layers, the method can firstly establish a gas layer near-wellbore region drilling probability set with a plurality of gas layer thicknesses with relatively accurate representation effects by using the data of the drilled gas wells, and then determine the drilling position by using the gas layer near-wellbore region drilling probability set with the plurality of gas layer thicknesses, thereby solving the technical problem that the drilling position cannot be accurately determined in the prior art and achieving the technical effect of rapidly and accurately guiding the deployment of the new gas wells.

Based on the thought, the embodiment of the application provides a method for determining a drilling position. Specifically, fig. 1 is a process flow diagram of a method for determining a drilling location according to an embodiment of the present application. The method for determining the drilling position provided by the embodiment of the application can be implemented by the following steps.

S11: and acquiring logging data, core data, gas testing result data and gas layer thicknesses at a plurality of well points in the drilled gas well in the target area.

In one embodiment, the target area may be specifically an area in which a low permeability tight sandstone gas reservoir is distributed. Wherein, the hypotonic compact sandstone gas reservoir generally has the following characteristics: the single gas layer is relatively thin and small in scale, and a plurality of layers are stacked in space. In addition, the exploitation of the low-permeability tight sandstone gas reservoir mostly adopts development modes such as a fixed well pattern and/or a depletion mode to carry out specific gas reservoir exploitation at present. In specific implementation, when a depletion development mode is adopted for gas reservoir exploitation, after a gas well is put into operation, the yield of the gas well is gradually reduced along with the reduction of the formation pressure. To maintain long term steady production from a gas field, new wells (new gas wells) are typically deployed continuously each year to compensate for the reduction in the production of drilled gas wells.

In the embodiment, in order to find a relatively good drilling position to deploy a new gas well, a position within a certain distance range with the drilled gas well as the center can be determined as the drilling position by taking the drilled gas well as a reference, so as to deploy the new gas well. Wherein, the relatively good drilling position can be specifically understood as: the new gas well and the drilled gas well are deployed at the drilling location independently of each other, for example, the new gas well and the drilled gas well are deployed at the drilling location to extend into different gas layers. Therefore, the gas production rate of the new gas well cannot be lower and poor because the extended gas layer is produced by the drilled gas well in a depletion development mode before. At the same time, no other gas layers are distributed in the area between the drilling location and the drilled gas well location. Therefore, the gas reservoir resources in other gas layers can be prevented from being omitted, and the gas reservoir resources are not fully exploited.

In this embodiment, in specific implementation, the logging data, the core data, the gas test result data, and the gas layer thicknesses at multiple well points in the drilled gas well may be obtained with the drilled gas well as a reference, so as to perform subsequent analysis. The gas layer thickness at a plurality of well points in the drilled gas well can be specifically understood as follows: a drilled gas well may be drilled into the subsurface at multiple gas formations, and for each gas formation drilled into the drilled gas well, the longitudinal length of the gas formation drilled into the drilled gas well at the point in the well may be considered the gas formation thickness of the drilled gas well at the point in the current gas formation.

S12: and establishing a gas layer near-wellbore area drilling probability set with a plurality of gas layer thicknesses according to the logging data, the core data and the gas testing result data.

In this embodiment, the set of drilling probability of the near-wellbore region of the gas formation thickness may be a drilling probability table of the near-wellbore region of the gas formation thickness, and may be used to represent the probability of drilling the same gas formation as the drilled gas well at a certain specific gas formation thickness (or depth) position at a different horizontal distance from the drilled gas well.

In one embodiment, in order to establish a plurality of gas layer near wellbore region drilling probability sets representing gas layer thicknesses with relatively accurate characterization effects, the following method may be implemented.

S12-1: and establishing a thickness distribution probability curve of the target gas layer according to the logging data, the core data and the gas testing result data.

In this embodiment, in specific implementation, according to the logging data, the core data, and the gas testing result data, a statistical analysis of the gas bed thickness may be performed, and a corresponding relationship between different gas bed thicknesses (depths) and distribution probabilities may be determined, so as to draw a probability distribution curve, that is, a thickness distribution probability curve of a target gas bed. In specific implementation, the thickness distribution probability curve of the target gas layer can be established by rounding off the integral value of the thickness of the gas layer to be taken as the abscissa and taking the proportion of different gas layer thicknesses as the ordinate. Specifically, a schematic diagram of a gas layer thickness probability distribution curve of a low-permeability dense gas field can be obtained by referring to the determination method of the drilling position provided by the embodiment of the application shown in fig. 2. The specific proportion of the thicknesses of different gas layers in the target gas layer can be determined through the thickness distribution probability curve. Specifically, for example, the thickness of a certain gas layer can be divided into five specific cases of 1 meter, 2 meters, 3 meters, 4 meters and 5 meters by a rounding method, and then distribution probabilities corresponding to the thicknesses of the five gas layers are respectively determined, so that a distribution probability curve of the gas layer can be obtained.

S12-2: and determining the formation environment of the target gas layer according to the core data.

In this embodiment, in concrete implementation, the core data may be used as the indication data to analyze the specific formation environment of the target gas formation. For example, it may be determined from the core data whether the formation environment of the target gas formation is a river cause.

In this embodiment, it is further necessary to supplement that the core data may be combined to analyze a main gas production structure of the target gas formation, and a specific gas production structure in the target gas formation is taken as a reference to guide and determine a specific forming environment. Specifically, for example, the core data can be combined to analyze the target gas reservoir as a hypotonic-tight sandstone gas reservoir with a binary structure, wherein the sandstone reservoir can be further divided into two parts, namely a dominant gas-containing sand and a matrix reservoir. Specifically, a typical hypotonic-tight gas field reservoir binary structure characteristic profile diagram can be obtained by referring to the determination method of the well drilling position provided by the embodiment of the application shown in fig. 3. The main force gas-containing sand body is an actual gas layer, namely a natural gas production layer, the base reservoir storage capacity is poor generally, and cannot form a production layer, and the forming environment of the target gas layer can be determined more accurately according to the analysis result.

S12-3: and determining the width-thickness ratio of the target gas layer according to the forming environment of the target gas layer.

In the present embodiment, the aspect ratio of the target gas layer may specifically be a ratio of a gas layer width (horizontal direction) to a maximum gas layer thickness (vertical direction) in the target gas layer.

In the present embodiment, the gas layer is generally circular or elliptical in the horizontal direction, and the radii of the major axis and the minor axis are mostly considered to be approximately the same, and may be represented by r; in the vertical direction, the gas layer can be approximately regarded as a cross-sectional structure with a convex top and a flat bottom, wherein the thickness of the gas layer in the middle of the cross-sectional structure is the largest, and is the largest thickness of the gas layer, which can be recorded as h_maxThe gas layer thickness is gradually reduced towards the two sides by taking the position corresponding to the maximum thickness as the center. In determining the specific value of the aspect ratio of the target gas layer, the following formula can be used: 2r_max/h_maThat is, the ratio of the width of the gas layer to the maximum thickness of the gas layer in the target gas layer is obtained as the width-thickness ratio of the gas layer, and the ratio is recorded as_x. Specifically, a schematic diagram of the shape of the top, bottom and convex space of the low-permeability and dense gas field gas layer can be obtained by referring to the method for determining the drilling position provided by the embodiment of the present application shown in fig. 4.

In this embodiment, it is necessary to supplement that the specific numerical value of the aspect ratio is different due to different gas field specific forming environments and different reservoir geological conditions. Therefore, the corresponding width-to-thickness ratio can be determined according to the formation environment of the target gas layer. Specifically, for example, when the formation environment of the target gas layer is determined to be a river cause, the range of the width-thickness ratio of the hypotonic-tight sandstone gas reservoir of the river cause is determined to be 80-120 by looking up data and the like. In the present embodiment, the aspect ratio of the target gas layer corresponding to the formation environment may be determined to be 100 by taking an average value.

S12-4: and establishing a gas layer near-wellbore area drilling probability set with a plurality of gas layer thicknesses according to the width-thickness ratio of the target gas layer and the thickness distribution probability curve of the target gas layer.

In this embodiment, in a specific implementation, the set of drilling probabilities of the near wellbore region of the gas formation of each of the plurality of gas formation thicknesses may be determined for a specific situation corresponding to each of the plurality of gas formation thicknesses. In specific implementation, the thickness of each gas layer can be discussed in a classified manner, and the probability that the drilling of the near wellbore area meets the gas layer where the drilled gas well is located under different types of conditions is discussed by combining the specific width-thickness ratio of the target gas layer and the thickness distribution probability curve of the target gas layer; and then combining the corresponding discussion results of different types of conditions to establish a gas layer near-wellbore region drilling probability set of each gas layer thickness.

In this embodiment, in specific implementation, a target gas well with gas layer thicknesses of 1 meter, 2 meters, 3 meters, 4 meters and 5 meters may be taken as an example to specifically describe how to establish a gas layer near-wellbore region drilling probability set with multiple gas layer thicknesses. Specifically, the near zone may be a range region defined by taking the drilled gas well as the center and taking an integer multiple of 50m as the distance from the drilled gas well.

In this embodiment, a drilled gas well (also referred to as a theoretical gas well) may be selected as S1, and assuming that there are 5 gas formations drilled in the gas well S1, and the thicknesses of the gas formations (i.e., the thicknesses of the gas formations at the well point) when the 5 gas formations are drilled are respectively 1m, 2m, 3m, 4m, and 5m, a gas formation near-wellbore region drilling probability set with a plurality of gas formation thicknesses is respectively established as follows. In the present embodiment, the east direction is taken as an example for description, and the other directions may be performed by referring to the determination manner of the east direction.

(1) Establishing a gas layer near-wellbore region drilling probability set with the gas layer thickness (well point thickness) of 5m

In this embodiment, it is considered that the drill encounters a 5m thick gas formation at the well point, i.e. the gas formation is 5m thick. Since this thickness is 5m, which is the maximum of the gas layer thicknesses encountered by all the bits, there is only one case. Specifically, a schematic diagram of the near-wellbore area distribution of a gas reservoir with a well point thickness of 5m can be obtained by referring to the method for determining the drilling position shown in fig. 5 and provided according to the embodiment of the application.

Considering that the formation environment of the air layer is a river cause, the corresponding width-to-thickness ratio may be 100. And determining the gas layer width of the gas layer to be 500m according to the gas layer thickness and the width-thickness ratio. Further, it can be determined that the length of the current air layer extending to the east direction may be 250m, so that the probability of the drill encountering the air layer in the range of 250m horizontally can be determined as 100% according to the thickness distribution probability curve of the target air layer, and the probability of the drill encountering the air layer in the range of more than 250m can be determined as 0. And then a gas layer near wellbore zone drilling probability set with the gas layer thickness (well point thickness) of 5m can be established through statistics, namely the gas layer near wellbore zone drilling probability P with the well point thickness of 5m_5mThe contents of the prediction table may be specifically referred to as those shown in table 1.

TABLE 1 probability of drilling in near wellbore region of gas zone with well point thickness of 5m_5mPrediction table

(2) Establishing a gas layer near-wellbore region drilling probability set with the gas layer thickness (well point thickness) of 4m

In this embodiment, it is contemplated that the drill encounters a 4m thick gas formation at the well point, and there is a 5m thick gas formation thickness greater than this. Therefore, the analysis can be discussed separately in two types of cases. Specifically, the predicted well-point thickness 4m gas layer near-wellbore area distribution intention can be obtained by the method for determining the drilling position according to the embodiment of the application, which is shown in fig. 6.

Type case one: the drill encounters a gas layer with a maximum thickness of 4m

In this type of case, the drill encounters a relative probability P of a gas layer with a maximum thickness of 4m_4m ¹The thickness distribution probability curve of the target gas layer can be determined to be 66.67%, and the width of the gas layer can be determined to be 400m based on the gas layer with the maximum thickness of 4m according to the measurement of the width-thickness ratio of 100. The rightwardly east extension may be 200m, and it may be determined that the probability of encountering such a gas layer is 66.67% over a horizontal 200m range, and 0 over a 200m range.

Type two: side of drill meeting gas layer with maximum thickness of 5m

In this type of case, the above-mentioned relative probability P of drilling into the side of the air layer with 4m thickness in the air layer of 5m maximum thickness_4m ²According to the thickness distribution probability curve of the target gas layer, the probability of drilling in the gas layer within the range of 300m is determined to be 33.33%, the maximum thickness of the gas layer is 5m, the elongation towards the east side can be 300m, and the probability of drilling in the gas layer within the range of 300m is determined to be 33.33%, and the probability of drilling in the gas layer within the range of more than 300m is determined to be 0, wherein the width-thickness ratio is 100.

Combining the results of the above two types of analysis, it is possible to determine the probability P that a 4m gas zone is drilled in the near zone for a well point thickness (i.e., a gas zone thickness)_4m＝P_4m ¹+P_4m ². By combining the analysis results, a gas layer near-wellbore region drilling probability set with the gas layer thickness (well point thickness) of 4m can be statistically established, namely the gas layer near-wellbore region drilling probability P with the well point thickness of 4m_5mA prediction table. Specific reference may be made to the details shown in table 2. Therefore, the following steps are carried out: the probability of drilling in the air layer within the range of 200m is 100%, the probability of drilling in the air layer within the range of 200-300 m is 33.33%, and the probability of drilling in the air layer within the range of more than 300m is 0.

TABLE 2 probability of drilling in near wellbore region of 4m well point thickness gas layer P_4mPrediction table

In this embodiment, it is to be added that, in specific implementation, the distribution probabilities of the gas layer thicknesses 4m and 5m may be determined to be 20% and 10% respectively according to the thickness distribution probability curve of the target gas layer; and then the relative probability of the air layer with the maximum thickness of 4m in drilling can be determined by a relative probability method as follows: p _4m ¹20%/(20% + 10%) 66.67% and a relative probability P of drilling encountering a gas layer with a maximum thickness of 5m (i.e. 4m encountered is the side of a gas layer with a maximum thickness of 5 m)_4m ¹10%/(20% + 10%) 33.33%. Other relative probability determinations may be specifically performed with reference to the above-described methodFurther description of the present application is omitted herein.

(3) Establishing a gas layer near-wellbore region drilling probability set with the gas layer thickness (well point thickness) of 3m

In this embodiment, it is considered that the drill encounters a 3m thick gas formation at the well point, and there is a 5m, 4m thick gas formation thickness greater than this. Therefore, the analysis can be discussed separately in three types of cases. Specifically, a schematic diagram of the near-wellbore area distribution prediction of a gas reservoir with a well point thickness of 3m can be obtained by referring to the method for determining the drilling position shown in fig. 7 and provided according to the embodiment of the application.

Type case one: air layer with maximum thickness of 3m in drilling process

In this type of case, the above-mentioned drill encounters a relative probability P of a gas layer with a maximum thickness of 3m_3m ¹According to the thickness distribution probability curve of the target gas layer, the probability of drilling in the gas layer within the horizontal 150m range is 57.14%, the maximum thickness of the gas layer is 3m, the elongation towards the east side can be 150m, and the probability of drilling in the gas layer within the horizontal 150m range is 0, wherein the width-thickness ratio is 100.

Type two: side part of drill meeting gas layer with maximum thickness of 4m

In this type of case, the drill encounters a relative probability P of the side of the 4m gas layer_3m ²According to the thickness distribution probability curve of the target gas layer, the maximum thickness of the gas layer is 4m, the elongation towards the east side can be determined as 250m, and the probability of drilling the gas layer within the range of 250m horizontally can be determined as 28.57%, and the probability of drilling the gas layer within the range of more than 250m is 0, wherein the measured ratio of width to thickness is 100.

Type case three: side of drill meeting gas layer with maximum thickness of 5m

In this type of case, the drill encounters a relative probability P of the side of the 5m gas layer_4m ³According to the thickness distribution probability curve of the target gas layer, the probability of drilling in the range of 350m horizontally is 14.29%, the maximum thickness of the gas layer is 5m, the elongation towards the east side can be determined to be 350m, and the range of more than 350m is drilledThe probability of encountering this air layer is 0.

Combining the results of the above discussion analysis of the three types of cases, it was possible to determine the well point thickness (i.e., the gas zone thickness) as the probability of a 3m gas zone being drilled in the near zone: p_3m＝P_3m ¹+P_3m ²+P_3m ³. By combining the analysis results, a gas layer near-wellbore region drilling probability set with a gas layer thickness (well point thickness) of 3m can be statistically established, namely the gas layer near-wellbore region drilling probability P with the well point thickness of 3m_3mA prediction table. Specific reference may be made to the details shown in table 3. Therefore, the following steps are carried out: the probability of the drill meeting the air layer within 150m in the horizontal direction is 100 percent, the probability of the drill meeting the air layer within 150-250 m in the horizontal direction is 42.86 percent, the probability of the drill meeting the air layer within 250-350 m in the horizontal direction is 14.29 percent, and the probability of the drill meeting the air layer within more than 350m in the horizontal direction is 0.

TABLE 3 probability of drilling in near wellbore region of gas layer with well point thickness of 3m_3mPrediction table

(4) Establishing a gas layer near-wellbore region drilling probability set with the gas layer thickness (well point thickness) of 2m

In this embodiment, it is considered that the drill encounters a 2m thick gas formation at the well point, and there are 5m, 4m, 3m thick gas formations above that thickness. Therefore, the analysis can be discussed separately in four types of cases. Specifically, a schematic diagram of the near-wellbore area distribution prediction of a gas reservoir with a well point thickness of 2m can be obtained by referring to the method for determining the drilling position shown in fig. 8 and provided according to the embodiment of the application.

Type case one: air layer with maximum thickness of 2m in drilling process

In this type of case, the above-mentioned drill encounters a relative probability P of a gas layer with a maximum thickness of 2m_2m ¹The probability curve of the thickness distribution of the target gas layer can be determined to be 22.22%, the maximum thickness of the gas layer is 2m, the elongation towards the east can be determined to be 100m, and the probability of drilling the gas layer within 100m of the horizontal range can be determined to be 22.22% and more than 10%, measured according to the width-thickness ratio of 100The probability of a 0m range drilling encountering this air layer may be determined to be 0.

Type two: side part of drill meeting air layer with maximum thickness of 3m

In this type of case, the above-mentioned drill encounters the relative probability P of the side of the gas layer having a maximum thickness of 3m_2m ²According to the thickness distribution probability curve of the target gas layer, the maximum thickness of the gas layer is 3m, the elongation towards the east side can be determined as 200m, and therefore the probability of drilling in the range of 200m horizontally can be determined as 44.44%, and the probability of drilling in the range of more than 200m horizontally can be determined as 0, wherein the thickness distribution probability curve can be determined as 44.44%.

Type case three: side part of drill meeting gas layer with maximum thickness of 4m

In this type of case, the drill encounters a relative probability P of a gas layer with a maximum thickness of 4m_2m ³According to the thickness distribution probability curve of the target gas layer, the maximum thickness of the gas layer is 4m, the elongation towards the east side can be determined as 300m, the probability of drilling the gas layer within the range of 300m horizontally can be determined as 22.22%, and the probability of drilling the gas layer within the range of more than 100m horizontally can be determined as 0, wherein the thickness distribution probability curve can be determined as 22.22%.

Type case four: side of drill meeting gas layer with maximum thickness of 5m

In this type of case, the drill encounters a relative probability P of a gas layer with a maximum thickness of 5m_2m ⁴According to the thickness distribution probability curve of the target gas layer, the thickness distribution probability curve can be determined to be 11.11%, the maximum thickness of the gas layer is 5m, the elongation towards the east side can be determined to be 400m, therefore, the probability of drilling in the gas layer within the range of 400m on the horizontal can be determined to be 11.11%, and the probability of drilling in the gas layer within the range of more than 400m can be determined to be 0.

Combining the results of the above-discussed analysis of the four types of cases, it is possible to determine the well point thickness (i.e., the gas zone thickness) as the probability that a 2m gas zone is encountered in the near wellbore zone: p_2m＝P_2m ¹+P_2m ²+P_2m ³+P_2m ⁴. Combining the above analysis results, the gas layer thickness (well point thickness) can be statistically established as2m gas layer near wellbore zone drilling probability set, namely 2m gas layer near wellbore zone drilling probability P with well point thickness_2mA prediction table. Specific reference may be made to the details shown in table 4. Therefore, the following steps are carried out: the probability of drilling in the range of 100m in the horizontal direction to meet the air layer is 100 percent, the probability of drilling in the range of 100-200 m in the horizontal direction to meet the air layer is 77.77 percent, the probability of drilling in the range of 200-300 m in the horizontal direction to meet the air layer is 33.33 percent, the probability of drilling in the range of 300-400 m in the horizontal direction to meet the air layer is 11.11 percent, and the probability of drilling in the range of more than 400m in the horizontal direction to meet the air layer is 0.

TABLE 4 probability of drilling in the near wellbore region of 2m well point thickness gas layer_2mPrediction table

(5) Establishing a gas layer near-wellbore region drilling probability set with the gas layer thickness (well point thickness) of 1m

In this embodiment, it is contemplated that the drill encounters a 1m thick gas formation at the well point, and there are 5m, 4m, 3m, 2m thick gas formations above which the thickness is greater. Therefore, the analysis can be discussed separately in five types of cases. Specifically, a schematic diagram of the near-wellbore area distribution prediction of a gas reservoir with the well point thickness of 1m can be obtained by referring to the method for determining the drilling position shown in fig. 9 and provided according to the embodiment of the application.

Type case one: gas layer with maximum thickness of 1m in drilling

In this type of case, the above-mentioned drill encounters a relative probability P of a gas layer of maximum thickness 1m_1m ¹According to the thickness distribution probability curve of the target gas layer, the probability curve can be determined to be 10%, the maximum thickness of the gas layer is 1m, the elongation towards the east side can be determined to be 50m, therefore, the probability of drilling in the range of 50m on the horizontal surface to the gas layer can be determined to be 10%, and the probability of drilling in the range of more than 50m to the gas layer can be determined to be 0.

Type two: side part of drill meeting air layer with maximum thickness of 2m

In this type of case, the drill encounters a lateral relative probability P of a gas layer with a maximum thickness of 2m_1m ²According to the target gas layerThe thickness distribution probability curve can be determined as 20%, the maximum thickness of the gas layer is 2m, the elongation towards the east can be determined as 150m, and the probability of drilling in the range of 150m horizontally to the gas layer can be determined as 20%, and the probability of drilling in the range of more than 150m to the gas layer can be determined as 0, measured according to the width-to-thickness ratio of 100.

Type case three: side part of drill meeting air layer with maximum thickness of 3m

In this type of case, the drill encounters a lateral relative probability P of a gas layer with a maximum thickness of 3m_1m ³According to the thickness distribution probability curve of the target gas layer, the probability curve can be determined to be 40%, the maximum thickness of the gas layer is 3m, the elongation towards the east side can be determined to be 250m, therefore, the probability of drilling in the range of 250m horizontally to the gas layer can be determined to be 40%, and the probability of drilling in the range of more than 250m to the gas layer can be determined to be 0.

Type case four: side part of drill meeting gas layer with maximum thickness of 4m

In this type of case, the drill encounters a lateral relative probability P of a gas layer with a maximum thickness of 4m_1m ⁴According to the thickness distribution probability curve of the target gas layer, the probability curve can be determined to be 20%, the maximum thickness of the gas layer is 4m, the elongation towards the east side can be determined to be 350m, therefore, the probability of drilling in the range of 350m on the horizontal surface to the gas layer can be determined to be 20%, and the probability of drilling in the range of more than 350m to the gas layer can be determined to be 0.

Type case five: side of drill meeting gas layer with maximum thickness of 5m

In this type of case, the drill encounters a lateral relative probability P of a gas layer with a maximum thickness of 5m_1m ⁵According to the thickness distribution probability curve of the target gas layer, the probability curve can be determined to be 10%, the maximum thickness of the gas layer is 5m, the elongation towards the east can be determined to be 450m, therefore, the probability of drilling in the range of 450m on the horizontal surface to the gas layer can be determined to be 10%, and the probability of drilling in the range of more than 450m to the gas layer can be determined to be 0.

Combining the results of the above-discussed analysis of the five types of cases, it can be determined that the well point thickness (i.e., gas layer thickness) is 1m and the gas layer is located in the near wellbore areaProbability of drilling encounter: p_1m＝P_1m ¹+P_1m ²+P_1m ³+P_1m ⁴+P_1m ⁵. By combining the analysis results, a gas layer near-wellbore region drilling probability set with the gas layer thickness (well point thickness) of 1m can be statistically established, namely the gas layer near-wellbore region drilling probability P with the well point thickness of 1m_1mA prediction table. Specific reference may be made to the details shown in table 5. Therefore, the following steps are carried out: the probability of drilling in a range of 50m in the horizontal direction to meet the air layer can be determined as 100%, the probability of drilling in a range of 50-150 m in the horizontal direction to meet the air layer can be determined as 90%, the probability of drilling in a range of 150-250 m in the horizontal direction to meet the air layer can be determined as 70%, the probability of drilling in a range of 250-350 m in the horizontal direction to meet the air layer can be determined as 30%, the probability of drilling in a range of 350-450 m in the horizontal direction to meet the air layer can be determined as 10%, and the probability of drilling in a range of more than 450m to meet the air layer is 0.

TABLE 5 probability of drilling in the near wellbore region of 1m well point thickness gas layer_1mPrediction table

S13: and determining a drilling position according to the gas layer near-wellbore region drilling probability set of the plurality of gas layer thicknesses and the gas layer thicknesses at a plurality of well points in the drilled gas well.

In one embodiment, after establishing the set of drilling probabilities of the near-wellbore region of the gas zone with the plurality of gas zone thicknesses, in order to accurately determine the drilling position of the new gas well so as to deploy the new gas well, the following steps may be performed:

s13-1: and determining a relation curve of the drilling probability and the near-well distance according to the gas layer thicknesses at the plurality of well points and the gas layer near-well zone drilling probability set of the plurality of gas layer thicknesses, wherein the near-well distance is the distance from the drilled gas well.

In this embodiment, the relationship curve between the drilling probability and the near-wellbore distance is also referred to as a relationship curve diagram between the simultaneous drilling probability of multiple gas formations and the near-wellbore distance, and may be specifically used to represent the combined drilling probability of multiple gas formations. Thus, it can be used as a guide to determine the location of new gas wells so that drilling encounters to the same gas formation can be avoided.

S13-2: and determining the drilling position according to the relation curve of the drilling probability and the near-well distance.

In this embodiment, the determining the drilling location according to the relationship between the drilling probability and the near-wellbore distance may include the following steps:

s1: determining the near well distance with the drilling probability of 0 as a threshold distance according to the relation curve of the drilling probability and the near well distance;

s2: determining a location of the drilled gas well at the threshold distance as the drilling location.

In the present embodiment, the region outside the range defined by the near-wellbore distance having the drilling probability of 0 may be regarded as the minimum range in which simultaneous drilling of any of the gas formations encountered by the drilled gas well is impossible. Therefore, deploying new gas wells at the determined drilling locations in the area may better avoid drilling all gas formations that have been drilled by the drilled gas wells, with relatively minimal cross-well effects.

In the present embodiment, taking 5 gas layer thicknesses of 1m, 2m, 3m, 4m, and 5m encountered by the drill as an example, the probability of each drilling in the near-wellbore region range of 0 to 500m can be determined from the set of drilling probabilities of the near-wellbore region of the gas layer corresponding to the gas layer thicknesses: p_1m、P_2m、P_3m、P_4m、P_5m. And determining the probability of simultaneous drilling of 5 gas layers in the near-wellbore region according to the probability of each drilling: p ═ P_1m×P_2m×P_3m×P_4m×P_5mAnd further, a relation curve of the drilling probability and the near-well distance can be established, namely a schematic diagram of the relation curve of the simultaneous drilling probability and the near-well distance of a plurality of gas layers. In particular, the graph of the simultaneous drilling probability and the near well distance of the S1 well 5 gas layers obtained by the determination method of the drilling position provided by the embodiment of the application shown in FIG. 10 is shownFigure (a).

In an embodiment, according to the relation curve between the drilling probability and the near-well distance, the probability that 5 gas layers of the drilled gas well S1 are drilled simultaneously in the near-well zone range of 0-500 m is obtained through statistics, so that a gas layer drilling probability prediction table in the near-well range of the drilled gas well S1 is established, and the details shown in table 6 can be specifically referred to. Therefore, the following steps are carried out: as the distance from the well point becomes greater, the probability that the 5 gas layers will be encountered simultaneously becomes lower. The probability of simultaneous drilling of 5 gas layers within a range 50m away from the horizontal distance of the drilled gas well can be determined to be 100%, the probability of simultaneous drilling of 5 gas layers within a range 50-100 m away from the horizontal distance of the drilled gas well can be determined to be 90%, the probability of simultaneous drilling of 5 gas layers within a range 100-150 m away from the horizontal distance of the drilled gas well can be determined to be 70%, the probability of simultaneous drilling of 5 gas layers within a range 150-200 m away from the horizontal distance of the drilled gas well can be determined to be 23%, and the probability of simultaneous drilling of 5 gas layers within a range 200-250 m away from the horizontal distance of the drilled gas well can be determined to be 3%.

TABLE 6 prediction table of gas formation drilling probability in near-well range of drilled gas well S1

And then the drilling position of the new gas well can be more accurately selected according to the table 6. Specifically, for example, in order to avoid relatively severe interpore effects with the drilled gas well, the drilling location of the newly deployed gas well may be selected to be 300m or more away from the location of the drilled gas well. In addition, further to ensure that none of the drilled encountering gas zones of the drilled gas wells S1 in the near-wellbore zone coincide with the new gas well drill, and that the interpore impact is relatively minimal, the drilling location of the newly deployed gas well may be selected to be greater than or equal to 500m from the drilled gas well.

In the embodiment of the application, compared with the prior art, a gas layer near-wellbore area drilling probability set with more accurate representation effect and a plurality of gas layer thicknesses is established by fully utilizing the data of drilled gas wells; and determining the drilling position by utilizing the drilling probability set of the gas layer near wellbore zone with a plurality of gas layer thicknesses, thereby solving the technical problem that the drilling position cannot be accurately determined in the existing method and achieving the technical effect of rapidly and accurately guiding the deployment of a new gas well.

In an embodiment, in a specific implementation, after obtaining the thickness distribution probability curve of the target gas layer, in order to obtain the thickness distribution probability curve of the target gas layer with a more accurate characterization effect, the method may further include the following steps: acquiring logging data, result explanation data and field measurement data of a drilled gas well in a target area; and correcting the thickness distribution probability curve of the target gas layer according to the logging data, the result interpretation data and the field measurement data to obtain the corrected thickness distribution probability curve of the target gas layer. Correspondingly, the establishing of the gas zone near-wellbore area drilling probability set with a plurality of gas zone thicknesses according to the width-thickness ratio of the target gas zone and the thickness distribution probability curve of the target gas zone may specifically include: and establishing a gas layer near-wellbore area drilling probability set with a plurality of gas layer thicknesses according to the width-thickness ratio of the target gas layer and the corrected thickness distribution probability curve of the target gas layer. Therefore, the thickness distribution probability curve of the target gas layer with relatively more accurate representation effect can be obtained.

In one embodiment, the determining the drilling probability-near-wellbore distance relationship curve according to the gas layer thicknesses at the plurality of well points and the set of gas layer near-wellbore zone drilling probabilities of the plurality of gas layer thicknesses may be implemented by:

s1: and selecting a plurality of gas layer near-wellbore region drilling probability sets meeting the required gas layer thickness from the gas layer near-wellbore region drilling probability sets of the plurality of gas layer thicknesses according to the gas layer thicknesses at the plurality of well points.

In this embodiment, the plurality of gas formations with the required gas formation thickness may be gas formations with a gas formation thickness actually encountered by the drilled gas well. Specifically, for example, it may be determined that the thickness of a certain target gas layer may include five cases, i.e., 5m, 4m, 3m, 2m, and 1m, according to a thickness distribution probability curve of the certain target gas layer, and during actual construction, a drilled gas well only encounters three cases, i.e., 2m, 4m, and 5m, so that the cases, i.e., 2m, 4m, and 5m, of the gas layer thickness may be regarded as satisfactory cases, and accordingly, a gas layer near wellbore zone drilling probability set with a gas layer thickness (wellbore point thickness) of 2m, a gas layer near wellbore zone drilling probability set with a gas layer thickness (wellbore point thickness) of 4m, and a gas layer near wellbore zone drilling probability set with a gas layer thickness (wellbore point thickness) of 5m may be screened as a gas layer near wellbore zone drilling probability set with a gas layer thickness satisfying the requirements.

S2: and establishing a relation curve of the drilling probability and the near-well distance according to the set of the drilling probability of the near-well zone of the gas layer with the gas layer thickness meeting the requirements.

In this embodiment, in a specific implementation, the drilling probabilities of the gas layers with the corresponding thicknesses in the gas layer near wellbore zone drilling probability set of each gas layer near wellbore zone drilling probability set of the gas layer near wellbore zone with the gas layer thickness meeting the requirements in the plurality of gas layer near wellbore zone drilling probability sets within different horizontal distance ranges may be combined, so as to establish a relationship curve between the drilling probability and the near wellbore distance.

In one embodiment, the target area may specifically include, but is not limited to, an area having a low permeability tight sand gas reservoir distributed therein. In specific implementation, the method for determining the drilling position provided by the embodiment of the application can be further expanded and applied to other areas with similar geological structure characteristics to the area with the low-permeability tight sandstone gas reservoir. The present application is not limited thereto.

From the above description, it can be seen that the method for determining the drilling position provided by the embodiment of the application establishes a gas layer near wellbore zone drilling probability set with more accurate characterization effects and a plurality of gas layer thicknesses by fully utilizing data of drilled gas wells; the drilling position is determined by utilizing the drilling probability set of the gas layer near wellbore zone with a plurality of gas layer thicknesses, so that the technical problem that the drilling position cannot be accurately determined in the conventional method is solved, and the technical effect of rapidly and accurately guiding the deployment of a new gas well is achieved; and the technical effect of quickly and accurately establishing a gas layer near-wellbore area drilling probability set with a plurality of gas layer thicknesses is achieved by specifically utilizing the width-thickness ratio of the target gas layer and the thickness distribution probability curve of the target gas layer.

Based on the same inventive concept, the embodiment of the present invention further provides a device for determining a drilling position, as described in the following embodiments. Since the principle of solving the problem of the device for determining the drilling position is similar to that of the method for determining the drilling position, the implementation of the device for determining the drilling position can be referred to that of the method for determining the drilling position, and repeated details are omitted. As used hereinafter, the term "unit" or "module" may be a combination of software and/or hardware that implements a predetermined function. Although the means described in the embodiments below are preferably implemented in software, an implementation in hardware, or a combination of software and hardware is also possible and contemplated. Referring to fig. 11, a structural diagram of a device for determining a drilling location provided in an embodiment of the present application is shown, where the device may specifically include: the acquiring module 21, the establishing module 22, and the determining module 23, which will be described in detail below.

The obtaining module 21 may be specifically configured to obtain logging data, core data, gas test result data, and gas layer thicknesses at multiple well points in a drilled gas well in a target area.

The establishing module 22 may be specifically configured to establish a gas zone near-wellbore region drilling probability set with multiple gas zone thicknesses according to the logging data, the core data, and the gas testing result data.

The determining module 23 may be specifically configured to determine a drilling location according to the set of near-wellbore zone drilling probabilities of the gas formations and the gas formation thicknesses at a plurality of well points in the drilled gas well.

In one embodiment, in order to establish a gas zone near-wellbore region drilling probability set with a plurality of gas zone thicknesses according to the logging data, the core data and the gas test result data, the establishing module 22 may specifically include the following structural units:

the first establishing unit is specifically used for establishing a thickness distribution probability curve of a target gas layer according to the logging data, the core data and the gas testing result data;

the first determining unit may be specifically configured to determine a formation environment of a target gas layer according to the core data;

the second determining unit may be specifically configured to determine a width-to-thickness ratio of the target gas layer according to a formation environment of the target gas layer;

the second establishing unit may be specifically configured to establish a gas zone near-wellbore region drilling probability set with multiple gas zone thicknesses according to the width-thickness ratio of the target gas zone and the thickness distribution probability curve of the target gas zone.

In one embodiment, in order to determine the drilling position according to the set of near-wellbore zone drilling probabilities of the plurality of gas layer thicknesses and the gas layer thicknesses at a plurality of well points in the drilled gas well, the determining module 23 may specifically include the following structural units:

the third determining unit may be specifically configured to determine a relation curve between the drilling probability and a near-well distance according to the gas formation thicknesses at the multiple well points and a gas formation near-well zone drilling probability set of the multiple gas formation thicknesses, where the near-well distance is a distance from a drilled gas well;

and the fourth determining unit can be specifically used for determining the drilling position according to the relation curve of the drilling encounter probability and the near-well distance.

The embodiments in the present specification are described in a progressive manner, and the same and similar parts among the embodiments are referred to each other, and each embodiment focuses on the differences from the other embodiments. In particular, for the system embodiment, since it is substantially similar to the method embodiment, the description is simple, and for the relevant points, reference may be made to the partial description of the method embodiment.

It should be noted that, the systems, devices, modules or units described in the above embodiments may be implemented by a computer chip or an entity, or implemented by a product with certain functions. For convenience of description, in the present specification, the above devices are described as being divided into various units by functions, and are described separately. Of course, the functionality of the units may be implemented in one or more software and/or hardware when implementing the present application.

Moreover, in the subject specification, adjectives such as first and second may only be used to distinguish one element or action from another element or action without necessarily requiring or implying any actual such relationship or order. References to an element or component or step (etc.) should not be construed as limited to only one of the element, component, or step, but rather to one or more of the element, component, or step, etc., where the context permits.

From the above description, it can be seen that the device for determining a drilling position provided in the embodiment of the present application establishes a gas formation near wellbore region drilling probability set with a plurality of gas formation thicknesses with a relatively accurate characterization effect by fully utilizing data of drilled gas wells through the establishment module; the drilling position is determined by the determining module by utilizing the drilling probability set of the gas layer near-wellbore area with the thickness of a plurality of gas layers, so that the technical problem that the drilling position cannot be accurately determined in the existing method is solved, and the technical effect of quickly and accurately guiding the deployment of a new gas well is achieved; and the technical effect of quickly and accurately establishing a gas layer near-wellbore area drilling probability set with a plurality of gas layer thicknesses is achieved by utilizing the width-thickness ratio of the target gas layer and the thickness distribution probability curve of the target gas layer through the establishing module.

In one example embodiment, the method and apparatus for determining the location of a well drilled according to the present application finds the location of a new well deployed in the vicinity of a well S38-16-3 drilled in a gas field. The specific implementation process can be executed by referring to the following contents.

In the example of the scenario, the selected drilled gas well to be researched is an actual gas well S38-16-3 in a certain low-permeability and dense gas field, and further, the drilling position of a new gas well can be determined by developing near zone gas layer drilling probability prediction according to logging data, core data, gas test result data of the drilled gas well of the gas well and gas layer thicknesses at a plurality of well points in the drilled gas well. The specific implementation process can comprise the following steps:

s1: establishing a thickness distribution probability curve of a target gas layer according to the logging data, the core data and the gas test result data, wherein the specifically determined thickness distribution probability curve of the target gas layer can refer to a schematic diagram of the gas layer thickness probability distribution curve of the low-permeability dense gas field shown in figure 2; determining the formation environment of the target gas layer as a river cause according to the core data; and determining the width-thickness ratio of the target gas layer to be 100 according to the formation environment of the target gas layer as a river cause.

S2: the gas layer composition of the S38-16-3 well is determined. Wherein, the gas layer that has drilled the gas well and has bored altogether has 4, and thickness is respectively: 2m, 3m, 2m and 1 m. Specifically, a schematic diagram of a profile of a gas layer structure of the S38-16-3 well obtained by applying the method and the device for determining a drilling position provided by the embodiments of the present application in one example scenario is shown in fig. 12, and a schematic diagram of a plot of the simultaneous drilling probability of 4 gas layers of the S38-16-3 well obtained by applying the method and the device for determining a drilling position provided by the embodiments of the present application in one example scenario is shown in fig. 13. Among them, the drilled gas well was put into production in 7 months of 2003.

S3: obtaining a plurality of groups of probabilities of drilling the gas layer at the near well distance of the gas layer thickness at a plurality of well points according to the gas layer near well zone drilling probability set of the plurality of gas layer thicknesses meeting the requirements; and multiplying the probabilities of the gas layer thickness near-well distances of the gas layer thickness at the well points with the same near-well distance in the probabilities of the gas layer thickness near-well distances of the gas layer thickness at the plurality of well points on the drilling encountering gas layer respectively to obtain a relation curve of the drilling encountering probability and the near-well distance, and then indicating the drilling position of the specific new gas well by using the relation curve. It should be noted that the multiplication processing listed above is only one combined processing manner, and in specific implementation, other processing manners may be selected and used according to specific situations and construction requirements, and the combined processing may be performed on the probabilities of the gas layer thickness at the well points with the same near-well distance from the multiple sets of the probabilities of the gas layer thickness at the multiple well points from the drilling encountering gas layer, so as to obtain the relationship curve between the drilling probability and the near-well distance. The present application is not limited thereto.

In the present scenario example, according to the relationship between the drilling probability and the near-well distance, it can be determined that the probability that 4 gas layers drilled by a drilled gas well in the near-well zone are simultaneously drilled is: p ═ P_2m×P_2m×P_3m×P_1m. Analysis shows that: the probability that 4 gas layers are drilled and encountered simultaneously within a distance of 50m from an S38-16-3 well drilled is 100%, 90% within a distance of 50-100 m, 54.53% within a distance of 100-150 m, 18.15% within a distance of 150-200 m, 3.33% within a distance of 200-250 m, 0.48% within a distance of 250-300 m and 0.05% within a distance of 300-350 m. In order to avoid serious well-to-well influence, the drilling position of the new gas well is specifically selected to be more than 400m away from the S36-16-3 well. Specifically, the table 7 shows a table for predicting the probability of gas formation drilling in the near-well range of S38-16-3. According to the contents shown in table 7, if it is to be further ensured that none of the gas formations of the S38-16-3 wells are drilled by the new well in the near zone, and the interpore impact is minimized, the drilling position of the newly deployed gas well may be determined to be a position greater than or equal to 500m away from the drilled gas well.

The comprehensive analysis can determine that: in order to effectively avoid relatively serious well-to-well influence, the drilling position of the new gas well can be determined to be greater than or equal to 400m from the S38-16-34 well; if it is desired to minimize cross-well effects, the drilling location of the new gas well may be determined to be greater than or equal to 500m from the S38-16-34 well.

TABLE 7S38-16-3 near-well in-range gas formation drilling probability prediction table

S4: according to the actual scene, the method for determining the drilling position provided by the application is subjected to specific effect verification and analysis.

In the example of the scene, the S6-J4 is a late stage well, is located in the positive west direction of the S38-16-6 well, has the distance of 383m and the production time of 12 months in 2008. The gas field production field well-to-well interference test shows that well-to-well interference exists between two wells, and that gas layer communication exists between the wells. Specifically, the S38-16-3 well plan well pattern obtained by applying the method and apparatus for determining well location provided by the embodiments of the present application in one example scenario shown in FIG. 14 can be referred to. The initial wellhead casing pressure of the S6-J4 well production is 16MPa, and the average wellhead casing pressure of the gas well put into operation in the early period of the gas field is 24MPa, which also shows that the pressure of the gas layer at the S6-J4 well is reduced due to the communication with the S38-16-6. Further analysis showed that: the after-drilled development wells S6-J4 are too short of the earlier developed wells S38-16-6, resulting in 2 wells with severe cross-well effects, which would be much reduced if the 2 wells were more than 400m apart.

Through the scene example, the method and the device for determining the drilling position provided by the embodiment of the application are verified, and a gas layer near wellbore area drilling probability set with more accurate characterization effects and a plurality of gas layer thicknesses is established by fully utilizing data of drilled gas wells; and then determining the drilling position by utilizing the drilling probability set of the gas layer near wellbore zone with a plurality of gas layer thicknesses, thereby really solving the technical problem that the drilling position cannot be accurately determined in the existing method and achieving the technical effect of quickly and accurately guiding the deployment of a new gas well.

Although various specific embodiments are mentioned in the disclosure of the present application, the present application is not limited to the cases described in the industry standards or the examples, and the like, and some industry standards or the embodiments slightly modified based on the implementation described in the custom manner or the examples can also achieve the same, equivalent or similar, or the expected implementation effects after the modifications. Embodiments employing such modified or transformed data acquisition, processing, output, determination, etc., may still fall within the scope of alternative embodiments of the present application.

Although the present application provides method steps as described in an embodiment or flowchart, more or fewer steps may be included based on conventional or non-inventive means. The order of steps recited in the embodiments is merely one manner of performing the steps in a multitude of orders and does not represent the only order of execution. When an apparatus or client product in practice executes, it may execute sequentially or in parallel (e.g., in a parallel processor or multithreaded processing environment, or even in a distributed data processing environment) according to the embodiments or methods shown in the figures. The terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, the presence of additional identical or equivalent elements in a process, method, article, or apparatus that comprises the recited elements is not excluded.

The devices or modules and the like explained in the above embodiments may be specifically implemented by a computer chip or an entity, or implemented by a product with certain functions. For convenience of description, the above devices are described as being divided into various modules by functions, and are described separately. Of course, in implementing the present application, the functions of each module may be implemented in one or more pieces of software and/or hardware, or a module that implements the same function may be implemented by a combination of a plurality of sub-modules, and the like. The above-described apparatus embodiments are merely illustrative, and for example, the division of the modules is merely a logical division, and other divisions may be realized in practice, for example, a plurality of modules or components may be combined or integrated into another system, or some features may be omitted, or not executed.

Those skilled in the art will also appreciate that, in addition to implementing the controller as pure computer readable program code, the same functionality can be implemented by logically programming method steps such that the controller is in the form of logic gates, switches, application specific integrated circuits, programmable logic controllers, embedded microcontrollers and the like. Such a controller may therefore be considered as a hardware component, and the means included therein for performing the various functions may also be considered as a structure within the hardware component. Or even means for performing the functions may be regarded as being both a software module for performing the method and a structure within a hardware component.

The application may be described in the general context of computer-executable instructions, such as program modules, being executed by a computer. Generally, program modules include routines, programs, objects, components, data structures, classes, etc. that perform particular tasks or implement particular abstract data types. The application may also be practiced in distributed computing environments where tasks are performed by remote processing devices that are linked through a communications network. In a distributed computing environment, program modules may be located in both local and remote computer storage media including memory storage devices.

From the above description of the embodiments, it is clear to those skilled in the art that the present application can be implemented by software plus necessary general hardware platform. Based on such understanding, the technical solutions of the present application may be embodied in the form of a software product, which may be stored in a storage medium, such as a ROM/RAM, a magnetic disk, an optical disk, or the like, and includes several instructions for enabling a computer device (which may be a personal computer, a mobile terminal, a server, or a network device) to execute the method according to the embodiments or some parts of the embodiments of the present application.

The embodiments in the present specification are described in a progressive manner, and the same or similar parts among the embodiments are referred to each other, and each embodiment focuses on the differences from the other embodiments. The application is operational with numerous general purpose or special purpose computing system environments or configurations. For example: personal computers, server computers, hand-held or portable devices, tablet-type devices, multiprocessor systems, microprocessor-based systems, set top boxes, programmable electronic devices, network PCs, minicomputers, mainframe computers, distributed computing environments that include any of the above systems or devices, and the like.

While the present application has been described by way of examples, those of ordinary skill in the art will appreciate that there are numerous variations and permutations of the present application that do not depart from the spirit of the present application and that the appended embodiments are intended to include such variations and permutations without departing from the present application.

Claims

1. A method of determining a drilling location, comprising:

establishing a gas layer near-wellbore area drilling probability set with a plurality of gas layer thicknesses according to the logging data, the core data and the gas testing result data; the method for establishing the gas layer near-wellbore region drilling probability set with a plurality of gas layer thicknesses according to the logging data, the core data and the gas testing result data comprises the following steps: establishing a thickness distribution probability curve of a target gas layer according to the logging data, the core data and the gas testing result data; determining the formation environment of a target gas layer according to the core data; determining the width-thickness ratio of the target gas layer according to the forming environment of the target gas layer; establishing a gas layer near-wellbore area drilling probability set with a plurality of gas layer thicknesses according to the width-thickness ratio of the target gas layer and the thickness distribution probability curve of the target gas layer;

2. The method of claim 1, further comprising:

3. The method of claim 1, wherein determining a drilling location from the set of near-zone drilling probabilities for the plurality of gas formation thicknesses and the gas formation thicknesses at the plurality of well points in the drilled gas well comprises:

4. The method of claim 3, wherein determining a drilling probability versus near-wellbore distance from the set of gas formation near-wellbore zone drilling probabilities for the plurality of gas formation thicknesses and the gas formation thicknesses at the plurality of well points comprises:

5. The method of claim 4, wherein establishing the drilling probability versus near-wellbore distance from the set of drilling probabilities for the near-wellbore region for the plurality of satisfactory gas formation thicknesses comprises:

6. The method of claim 1, wherein determining a drilling location from the relationship of the drilling probability and the near-wellbore distance comprises:

7. The method of claim 1, wherein the target area comprises an area having a low permeability tight sandstone gas reservoir distributed therein.

8. An apparatus for determining a drilling location, comprising:

the establishing module is used for establishing a gas layer near-wellbore area drilling probability set with a plurality of gas layer thicknesses according to the logging data, the core data and the gas testing result data; wherein the establishing module comprises: the first establishing unit is used for establishing a thickness distribution probability curve of a target gas layer according to the logging data, the rock core data and the gas testing result data; the first determining unit is used for determining the forming environment of the target gas layer according to the rock core data; the second determining unit is used for determining the width-thickness ratio of the target gas layer according to the forming environment of the target gas layer; the second establishing unit is used for establishing a gas layer near-wellbore area drilling probability set with a plurality of gas layer thicknesses according to the width-thickness ratio of the target gas layer and the thickness distribution probability curve of the target gas layer;

9. The apparatus of claim 8, wherein the determining module comprises: