Calculation method and model for three-dimensional parameters of permeability of horizontal well and application of calculation method and model

Abstract

The invention provides a method and a model for calculating three-dimensional parameters of permeability of a horizontal well and application of the model, and relates to the technical field of oil-gas exploration. The calculation method comprises the following steps: S1, carrying out differential comparison on interval transit time of a horizontal section and a vertical well section, counting a correction value of the interval transit time, and calculating a real interval transit time value; s2, calculating the porosity based on the interval transit time; S3, calculating the permeability; s4, calculating the permeability three-dimensional parameters of the horizontal well: establishing a three-dimensional permeability relational expression of the full-diameter core, taking the total permeability calculated under the vertical well model as a new horizontal permeability 1, and calculating the permeability three-dimensional parameters of the horizontal well according to the relationship among the new horizontal permeability 1, the horizontal permeability 2 and the vertical permeability. And determining the three-dimensional permeability calculated according to the three-dimensional permeability calibration logging of the full-diameter core. According to the method, the three-dimensional permeability of the horizontal well is finely calculated through the overall calculation method and the calculation model, the calculation precision is improved, and more accurate physical property parameters are provided for reservoir numerical simulation.

Description

Technical Field

[0001] The present invention belongs to the technical field of oil and gas exploration, and particularly relates to a calculation method and model for three-dimensional parameters of horizontal well permeability and their applications. Background Art

[0002] With the continuous deepening of oilfield exploration and development work and the continuous progress of reservoir numerical simulation technology, the requirements for the calculation accuracy of reservoir physical property parameters are getting higher and higher. The existing formation permeability calculation models are mainly established based on microscopic parameters and conventional logging curves, including establishing relevant relationships with porosity, and also widely using pore or particle microscopic parameters (pore radius, particle radius, specific surface area, tortuosity, irreducible water content, flow unit, etc.), and extensively using nuclear magnetic resonance logging (T2, nuclear magnetic resonance porosity) and resistivity logging (porosity, resistivity), followed by natural gamma logging.

[0003] Chinese Patent Invention 202110154244.5 discloses a formation permeability calculation method combining array acoustic logging and conventional logging, including (1) data preparation; (2) classification of core porosity-permeability relationships; (3) optimization of permeability-sensitive parameters; (4) establishment of a permeability calculation model; (5) optimization of the permeability model; (6) permeability calculation and error calculation. This invention is different from the conventional method of calculating permeability using porosity. It mainly combines array acoustic logging and conventional logging, considers various influencing factors, and designs corresponding permeability calculation models for formations with different porosity-permeability conditions to improve the calculation accuracy of formation permeability; using its calculation results can quantitatively analyze the permeability of the formation during the oil and gas exploration stage, and help the exploration and development of subsequent oil and gas reservoirs.

[0004] Chinese Patent Invention 202010832965.2 discloses a method and computer for calculating the well test permeability of a reservoir using logging data. It uses the method of reservoir classification to reflect that different levels of reservoirs within the perforated interval contribute differently to productivity. By assigning different weight coefficients of absolute permeability to different levels of reservoirs, the composite permeability of the reservoir in the perforated interval is calculated. Finally, the accurate calculation of well test permeability is achieved by establishing a functional relationship between the composite permeability and the well test interpreted permeability. This method can convert the absolute permeability of the reservoir interpreted by logging into the well test interpreted permeability to achieve the purpose of continuously evaluating the natural productivity of the reservoir.

[0005] Previously, during the process of oil reservoir exploration and permeability calculation, the traditional method used the same method for calculating the permeability of all wells, and the calculation accuracy was relatively low, which could no longer meet the requirements of reservoir numerical simulation well location deployment and guiding the completion and fracturing scheme of clastic rocks.

[0006] Although there are many calculation methods for permeability, the information obtained from horizontal well logging includes both horizontal permeability and vertical permeability. Currently, the permeability calculation models for horizontal wells and vertical wells are the same, and it is impossible to reflect the contribution of vertical permeability to the total permeability in horizontal wells. The permeability calculated by logging in vertical wells is the average permeability at a single depth point. At present, it is difficult to calibrate the three-dimensional permeability obtained from full-diameter core porosity and permeability analysis using well logging. Therefore, it is of great significance to provide a calculation method and model for the three-dimensional parameters of horizontal well permeability, and to accurately calculate the three-dimensional permeability of horizontal wells through an overall three-dimensional parameter calculation method and model. Summary of the Invention

[0007] In view of the problems existing in the prior art, the present invention provides a calculation method and model for three-dimensional parameters of horizontal well permeability and its application. Through the overall calculation method and model, the three-dimensional permeability of horizontal wells is accurately calculated, providing more accurate physical property parameters for reservoir numerical simulation, guiding the design of completion and fracturing schemes for clastic rocks, and subsequent measures.

[0008] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0009] First, the present invention provides a calculation method for three-dimensional parameters of horizontal well permeability, including the following steps:

[0010] S1. Sonic transit time (AC) curve correction: Differentially compare the sonic transit time of the horizontal section and the vertical section of the well, statistically calculate the correction amount of AC, and calculate the true AC value;

[0011] S2. Calculate porosity based on the AC value: Align and correct the core porosity and permeability data according to the logging curve, establish a relationship between AC and core porosity, and establish a porosity calculation model based on AC;

[0012] S3. Calculate permeability;

[0013] S4. Calculate the three-dimensional parameters of horizontal well permeability: Establish a relationship for three-dimensional permeability of the full-diameter core, use the total permeability calculated under the vertical well model as horizontal permeability 1, and determine the three-dimensional permeability calibrated by logging based on the relationship between horizontal permeability 1, horizontal permeability 2, and vertical permeability.

[0014] Preferably, in step S1, the horizontal section is the horizontal section of the horizontal well; the vertical section is the vertical section of the vertical well, and a differential comparison is performed.

[0015] More preferably, the differential comparison is a differential comparison between the horizontal section of the horizontal well and the vertical section of the vertical well in the same well.

[0016] Preferably, in step S1, the calculation of the true AC value is processed using a logging software module; the logging software is the THsand module built into Forward; the logging software module is an AC calculation module.

[0017] Preferably, in step S2, the logging curves are 9 logging curves, including: AC (acoustic time difference) logging curve, DEN (density) logging curve, CNL (compensated neutron) logging curve, GR (natural gamma) logging curve, CAL (hole diameter) logging curve, SP (natural potential) logging curve, RILD (deep induction resistivity) logging curve, RILM (medium induction resistivity) logging curve, RFOC (eight-lateral resistivity) logging curve.

[0018] Preferably, in step S2, the homing is core homing, and the correction is overburden correction.

[0019] Preferably, in step S2, the porosity calculation model is: the model formula is POR = X * AC + Y, where POR is the core porosity, AC is the acoustic time difference, and X and Y are the coefficients of the formula.

[0020] Preferably, in step S2, the establishment of the porosity calculation model is carried out using a porosity calculation module.

[0021] Preferably, in step S3, the calculation of the permeability is specifically: establishing a relationship between the core porosity and the core permeability, and calculating the permeability based on the relationship between the porosity calculated by AC and the core porosity and permeability, so as to establish a calculation model for the total permeability of the horizontal well.

[0022] Further preferably, in step S3, the establishment of the calculation model for the total permeability of the horizontal well is carried out using a total permeability calculation module.

[0023] Further preferably, in step S3, the calculation model for the total permeability of the horizontal well is: the model formula is PERM = X * e (Y*POR) , where POR is the core porosity, PERM is the core permeability, and X and Y are the coefficients of the formula.

[0024] Preferably, in step S4, the three-directional permeability of the full-diameter core includes horizontal permeability 1, horizontal permeability 2, and vertical permeability.

[0025] Further preferably, the horizontal permeability 1 is the permeability along the formation direction, and the horizontal permeability 2 is the permeability perpendicular to the formation direction.

[0026] Preferably, step S4 is specifically as follows: First, analyze the three-directional permeability of the full-diameter core, i.e., horizontal permeability 1, horizontal permeability 2, and vertical permeability, from the full-diameter core. Then, establish the relationships between horizontal permeability 1 and horizontal permeability 2, and between horizontal permeability 1 and vertical permeability respectively. Finally, take the total permeability calculated under the vertical well model as the new horizontal permeability 1, and determine the final horizontal permeability 1, horizontal permeability 2, and vertical permeability based on the relationships among the new horizontal permeability 1, horizontal permeability 2, and vertical permeability. The finally determined permeability is the three-directional permeability calibrated by well logging based on the three-directional permeability of the full-diameter core.

[0027] Preferably, step S4 needs to be carried out in the three-directional permeability parameter calculation module.

[0028] Preferably, after calculating the three-directional permeability in step S4, finally output the three-directional parameters of the horizontal well permeability through the output module.

[0029] Then, the present invention provides a porosity calculation model established by the above calculation method.

[0030] Furthermore, the present invention provides a calculation model of the total permeability of a horizontal well established by the above calculation method.

[0031] Furthermore, the present invention provides the application of the above porosity calculation model or the calculation model of the total permeability of a horizontal well in the calculation of well logging permeability parameters.

[0032] Preferably, the wells in the above application include horizontal wells, vertical wells, and vertical wells.

[0033] The present invention provides a system for calculating three-directional parameters of horizontal well permeability, including: an AC calculation module, a porosity calculation module, a total permeability calculation module, a three-directional permeability parameter calculation module, and an output module.

[0034] Finally, the present invention provides the application of the above calculation system in the calculation of three-directional parameters of horizontal well permeability.

[0035] Preferably, the AC calculation module is used to count the correction amount of the AC of the horizontal section of the horizontal well and the vertical section of the vertical well of the same well, and calculate the true AC value of the horizontal well.

[0036] Preferably, the porosity calculation module is used to perform core repositioning and overburden pressure correction on the core pore permeability data, and establish a porosity calculation model based on the corrected AC according to the relationship between AC and core porosity.

[0037] Preferably, the total permeability calculation module establishes a calculation model of the total permeability of a horizontal well based on the relationship between core porosity and core permeability and the porosity calculated by AC.

[0038] Preferably, based on the correlation between the three-dimensional permeability of the full diameter, i.e., horizontal permeability 1, horizontal permeability 2, and vertical permeability, the three-dimensional permeability calculation module for horizontal wells calculates the three-dimensional permeability of horizontal wells through the total permeability calculated by porosity.

[0039] Preferably, the output module outputs the three-dimensional parameters of the permeability of horizontal wells.

[0040] Compared with the prior art, the present invention has the following beneficial effects:

[0041] 1. The calculation method of the present invention realizes the accurate calculation of the pore permeability parameters of horizontal wells, provides accurate physical property parameters for reservoir numerical simulation, and strongly supports the well location deployment work.

[0042] 2. Compared with the prior art, the calculation method of the present invention has the advantage of accurately calculating the permeability in each direction of horizontal wells, especially highlighting the contribution of the vertical permeability in horizontal wells to the total permeability, more accurately meeting the well location deployment of reservoir numerical simulation and guiding the prediction of fragmentation completion fracturing and the precise exploitation of oil and gas, and realizing the contribution of the vertical permeability in horizontal wells to the total permeability. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 is the overall flowchart of the calculation method for the three-dimensional parameters of the permeability of horizontal wells according to the present invention.

[0044] Figure 2 is the AC-core porosity relationship diagram of the well according to the embodiment of the present invention.

[0045] Figure 3 is the core porosity-core permeability relationship diagram of the well according to the embodiment of the present invention.

[0046] Figure 4 is the horizontal permeability 1-horizontal permeability 2 relationship diagram of the well according to the embodiment of the present invention.

[0047] Figure 5 is the horizontal permeability 1-vertical permeability relationship diagram of the well according to the embodiment of the present invention.

[0048] Figure 6 is the technical effect comparison diagram between the calculation method of the present invention and the traditional method. DETAILED DESCRIPTION OF THE INVENTION

[0049] The following non-limiting examples can enable those of ordinary skill in the art to more comprehensively understand the present invention, but do not limit the present invention in any way. The following content is merely an exemplary illustration of the scope claimed by the present invention. Those skilled in the art can make various changes and modifications to the present invention based on the disclosed content, and such changes and modifications should also fall within the scope claimed by the present invention. When the examples give a numerical range, it should be understood that unless otherwise specified in the present invention, any value at both ends of each numerical range and any value between the two ends can be selected. Unless otherwise defined, all technical and scientific terms used in the present invention have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs. The present invention will be further described below by way of specific examples.

[0050] Example 1

[0051] In this example, the X well is located in the Tahe Oilfield and is a horizontal well; the rock characteristics are clastic rocks. The overall flow chart of the calculation method for the three-direction parameters of the horizontal well permeability is as Figure 1 shown for implementation.

[0052] Meanwhile, the calculation method for the three-direction parameters of the horizontal well permeability described in the present invention needs to be calculated through the calculation system for the three-direction parameters of the horizontal well permeability, including an AC calculation module, a porosity calculation module, a total permeability calculation module, a three-direction permeability calculation module for the horizontal well, and an output module.

[0053] The AC calculation module is used to count the correction amount of the AC between the horizontal section of the horizontal well and the vertical section of the vertical well in the same well, and calculate the true AC value of the horizontal well;

[0054] The porosity calculation module is used to perform core homing and overburden pressure correction on the core pore permeability data, and based on the relationship between AC and core porosity, establish a porosity calculation model according to the corrected AC;

[0055] The total permeability calculation module is used to establish a horizontal well total permeability calculation model based on the relationship between core porosity and core permeability and according to the porosity calculated by AC;

[0056] The three-direction permeability calculation module for the horizontal well is used to calculate the three-direction permeability of the horizontal well based on the correlation between the full-diameter three-direction permeability, namely horizontal permeability 1, horizontal permeability 2, and vertical permeability, and the total permeability calculated by porosity;

[0057] Preferably, the output module outputs the three-direction parameters of the horizontal well permeability.

[0058] A calculation method for the three-direction parameters of the permeability of a horizontal well (X well) includes the steps of:

[0059] Step S1: In clastic rocks, the calculation of permeability is closely related to the evaluation of porosity. When calculating permeability, the establishment of a porosity calculation model is a prerequisite. In horizontal wells (X wells), due to the heterogeneity caused by lithology differences and the influence of the wellbore environment, the porosity value calculated by the AC (acoustic time difference) measured by logging is too large, and AC needs to be corrected by curves. By making a differential comparison between the horizontal section of the horizontal well and the vertical section of the vertical well of the same well, the correction amount of AC is statistically calculated, and the logging software is used to process the THsand module (AC calculation module) connected to the Forward module to calculate the true AC value of the horizontal well and remove the influence of lithology and wellbore environment on AC.

[0060] Step S2: After completing the curve correction of AC, it is necessary to calculate the porosity based on AC; according to the 9 conventional logging curves AC, DEN, CNL, GR, CAL, SP, RILD, RILM, and RFOC, the core porosity and permeability data are corrected for core location and overburden pressure, and the relationship between AC and core porosity is established (such as Figure 2 A porosity calculation model is established based on AC, and the model formula is POR=X*AC+Y, where POR is the core porosity, AC is the acoustic wave time difference, and X and Y are the coefficients of the formula; this step is performed in the porosity calculation module.

[0061] Step S3: After completing the porosity modeling, the permeability is calculated. First, the relationship between the core porosity and the core permeability is established, and then the permeability is calculated based on the relationship between the porosity calculated by AC and the core porosity (core permeability) (e.g. Figure 3 The core porosity-core permeability relationship diagram of Well X shown in the figure is used to establish a calculation model for the total permeability of horizontal wells. The model formula is PERM = X*e (Y*POR) , where POR is the core porosity, PERM is the core permeability, and X and Y are coefficients of the formula; this step is performed in the total permeability calculation module.

[0062] Step S4: After the total permeability model of the horizontal well is established, the three-dimensional parameters of the horizontal well permeability are calculated. The full-diameter core can analyze the horizontal permeability 1 (along the formation direction), horizontal permeability 2 (vertical to the formation direction) and vertical permeability. According to the three-dimensional permeability of the full-diameter core, the horizontal permeability 1 and horizontal permeability 2 (such as Figure 4 ), horizontal permeability 1 and vertical permeability (such as Figure 5 )

[0063] Then, the total permeability calculated under the vertical well model is used as the new horizontal permeability 1. Based on the relationship between the new horizontal permeability 1, horizontal permeability 2, and vertical permeability, the final horizontal permeability 1, horizontal permeability 2, and vertical permeability are determined. The finally determined permeability is the three-way permeability calibrated by logging based on the three-way permeability of the full-diameter core.

[0064] Step S4 is carried out in the three-way permeability parameter calculation module.

[0065] Step S5: Output the three-way parameters of the horizontal well permeability through the output module.

[0066] Before the calculation method described in the present invention, the same method was adopted for calculating the permeability of all wells used, and the calculation accuracy was relatively low. Moreover, in the traditional method, the permeability calculation models of horizontal wells and vertical wells were the same, and the contribution of the vertical permeability to the total permeability in horizontal wells could not be reflected. It was difficult to calibrate the three-way permeability through full-diameter pore permeability analysis. However, by using the calculation method described in the present invention, when applied to the calculation of well logging permeability parameters in fields such as horizontal wells, vertical wells, and vertical wells, the calculation accuracy can be improved, providing more accurate physical property parameters for reservoir numerical simulation. The comparison diagram of the technical effects (calculation of horizontal well vertical permeability) between the traditional method and the method of the present invention is as Figure 6 shown, where the square box is the test well section and the high-yield part is obtained. Figure 6 In the figure, the first track is the depth, with the unit of meter. The second track is the lithology logging track, from top to bottom are natural gamma, with the unit of API and the scale of 0 - 150; well diameter, with the unit of in and the scale of 6 - 16; spontaneous potential, with the unit of mV and the scale of 0 - 100. The third track is the resistivity logging track, from top to bottom are M2R1 (eight-lateral resistivity), with the unit of Ω·m and the scale of 0.2 - 200; M2R3 (medium induction resistivity), with the unit of Ω·m and the scale of 0.2 - 200; M2R9 (deep induction resistivity), with the unit of Ω·m and the scale of 0.2 - 200. The fourth track is the porosity logging track, from top to bottom are density, with the unit of g / cm3 and the scale of 2 - 3; acoustic time difference, with the unit of μs / ft and the scale of 140 - 40; neutron porosity, with the unit of % and the scale of 45 to -15. The fifth track is POR (porosity), with the unit of % and the scale of 0 - 30. The sixth track is the calculated permeability, from top to bottom are vertical permeability (the final calculated result is the vertical permeability of the horizontal well), with the unit of MD and the scale of 0.1 - 1000; PERM (total permeability calculated by the traditional method), with the unit of MD and the scale of 0.1 - 1000. The seventh track is the interpretation conclusion.

[0067] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, rather than a limitation on the protection scope of the present invention. Any simple modification or equivalent replacement made by those of ordinary skill in the art to the technical solution of the present invention shall not depart from the essence and scope of the technical solution of the present invention.

Claims

1. A calculation method for three - dimensional parameters of horizontal well permeability, characterized in that, Including the steps: S1. Sonic travel time curve correction: Differentially compare the sonic travel times of the horizontal section and the vertical well section, statistically calculate the correction amount of the sonic travel time, and calculate the true sonic travel time value; S2. Calculate porosity based on the sonic travel time value: Homotopically position and correct the core porosity and permeability data according to the logging curves, establish a relationship between the sonic travel time and the core porosity, and establish a porosity calculation model based on the sonic travel time; S3. Calculate permeability; S4. Calculate the three-dimensional parameters of the horizontal well permeability: Establish a three-dimensional permeability relationship for the full-diameter core, take the total permeability calculated under the vertical well model as the horizontal permeability 1, and determine the three-dimensional permeability calibrated by logging according to the relationship between the horizontal permeability 1, the horizontal permeability 2 and the vertical permeability; 2. The calculation method according to claim 1, characterized in that, In step S1, the horizontal section is the horizontal section of the horizontal well; the vertical well section is the vertical well section of the vertical well, and differential comparison is carried out.

3. The calculation method according to claim 2, characterized in that, The differential comparison is to differentially compare the horizontal section of the horizontal well and the vertical well section of the vertical well of the same well.

4. The calculation method according to claim 1, characterized in that, In step S1, the calculation of the true sonic travel time value is processed by using a logging software module; the logging software module is a sonic travel time calculation module.

5. The calculation method according to claim 1, characterized in that, In step S2, the logging curves are 9 logging curves, including: AC, DEN, CNL, GR, CAL, SP, RILD, RILM, RFOC.

6. The calculation method according to claim 1, characterized in that, In step S2, the homotopic positioning is core homotopic positioning, and the correction is overburden correction.

7. The calculation method according to claim 1, characterized in that, In step S2, the porosity calculation model is: the model formula is POR = X * AC + Y, where POR is the core porosity, AC is the sonic travel time, and X and Y are the coefficients of the formula; the establishment of the porosity calculation model is carried out using a porosity calculation module.

8. The calculation method according to claim 1, characterized in that, In step S3, the calculation of permeability is specifically: establish a relationship between the core porosity and the core permeability, and calculate the permeability according to the relationship between the porosity calculated based on the sonic travel time and the core porosity and permeability, so as to establish a calculation model for the total horizontal well permeability.

9. The calculation method according to claim 8, characterized in that, In step S3, the calculation model of the total permeability of the horizontal well is established using the total permeability calculation module; the calculation model of the total permeability of the horizontal well is: the model formula is PERM = X * e (Y*POR) , where POR is the core porosity, PERM is the core permeability, and X and Y are the coefficients of the formula.

10. The calculation method according to claim 1, characterized in that, In step S4, the three-dimensional permeability of the full-diameter core includes the horizontal permeability 1, the horizontal permeability 2 and the vertical permeability; the horizontal permeability 1 is the permeability along the formation direction, and the horizontal permeability 2 is the permeability perpendicular to the formation direction.

11. The calculation method according to claim 1, characterized in that, Step S4 is specifically: First, analyze the three-dimensional permeability of the full-diameter core from the full-diameter core: the horizontal permeability 1, the horizontal permeability 2 and the vertical permeability; then, establish the relationships between the above-mentioned horizontal permeability 1 and the horizontal permeability 2, and the horizontal permeability 1 and the vertical permeability respectively; finally, take the total permeability calculated under the vertical well model as the new horizontal permeability 1, and determine the final horizontal permeability 1, the horizontal permeability 2 and the vertical permeability according to the relationship between the new horizontal permeability 1, the horizontal permeability 2 and the vertical permeability. The finally determined permeability is the three-dimensional permeability calibrated by logging according to the three-dimensional permeability of the full-diameter core; step S4 needs to be carried out in a three-dimensional permeability parameter calculation module.

12. The calculation method according to claim 1, characterized in that, After calculating the three-dimensional permeability in step S4, finally output the three-dimensional parameters of the horizontal well permeability through an output module.

13. A porosity calculation model established by the calculation method according to any one of claims 1 - 12.

14. A calculation model for the total permeability of a horizontal well established by the calculation method according to any one of claims 1 - 12.

15. Application of the porosity calculation model according to claim 13 or the calculation model for the total permeability of a horizontal well according to claim 14 in the calculation of well - logging permeability parameters.

16. A calculation system for three - dimensional parameters of horizontal well permeability, characterized in that, Including: An acoustic travel time calculation module, a porosity calculation module, a formation permeability calculation module, a three-direction parameter calculation module for permeability, and an output module.

17. Application of the calculation system according to claim 16 in the calculation of three - dimensional parameters of horizontal well permeability.

Images