Method and device for evaluating natural energy of fault control fracture-vuggy carbonate reservoir stratum

Abstract

The invention relates to the technical field of oil and gas reservoir development, in particular to a method and device for evaluating natural energy of a fault control fracture-vuggy carbonate reservoir stratum. Comprising the following steps: acquiring natural energy evaluation indexes of a plurality of developed wells on a developed oil reservoir block unit in a target stratum; according to the natural energy evaluation indexes of the developed wells and the actual natural energy conditions of the developed wells, determining the natural energy rating of the target stratum, obtaining the seismic upper reservoir evaluation parameters of the target stratum, and fitting a relational expression between the seismic upper reservoir evaluation parameters and the natural energy evaluation indexes; and obtaining seismic reservoir evaluation parameters of the undeveloped wells on the undeveloped oil reservoir block units in the target stratum, calculating natural energy evaluation indexes of the undeveloped wells according to the relational expression, and determining natural energy conditions of the undeveloped wells according to natural energy rating. According to the embodiment of the invention, the natural energy of the undeveloped unit stratum of the fault control fracture-vuggy carbonate reservoir is evaluated.

Description

Technical Field

[0001] The present invention relates to the technical field of oil and gas reservoir development, and in particular to a method and device for evaluating the natural energy of a fault-controlled fracture-cavity carbonate reservoir stratum. Background Art

[0002] Carbonate oil and gas reservoirs are an important area for oil and gas exploration and development and oil and gas reserve increase. At present, most carbonate oil and gas reservoirs are old in geological age, deeply buried, and have undergone multiple periods of tectonic movement transformation. The oil and gas reservoir types are mainly fracture-pore type and fracture-cave type. The oil and gas reservoirs show the characteristics of "diversified accumulation, complex structure, and differentiated reservoirs", which are mainly manifested in complex accumulation geological conditions, multiple reservoir types, strong heterogeneity, complex fluid types and distribution, and most wells show the characteristics of "one well, one layer, one system". From the perspective of oil and gas reservoir development characteristics, due to the many types of storage space in carbonate oil and gas reservoirs, most oil reservoirs are mainly fracture-pore type and karst fracture-cave type, and the development characteristics vary greatly. The main manifestations are: first, the initial production is high and the decline is fast. The carbonate reservoir space is composed of pores, caves and fractures with large scale differences. In the early stage of exploitation, the oil and gas in the large fractures and caves that are in a free-flowing state are produced first, and the production is high. However, as the pressure drops, some fractures close, and the oil and gas seepage in small-sized storage spaces such as intergranular pores, intercrystalline pores and microcracks is slow, making it difficult to effectively replenish, and the production shows a rapid decline; second, the presence of edge and bottom water is common, which has a great impact on the production. For fracture-pore and karst fracture-cave oil reservoirs, edge and bottom water can easily invade quickly along the fractures, causing the water content of the oil well to increase rapidly, or even violently, resulting in a decrease in oil production and a low recovery rate; third, water injection development of oil reservoirs is prone to water channeling, and water injection can easily advance along the fractures. On the one hand, the affected volume and oil displacement efficiency are reduced, and on the other hand, the separation and shielding effect of water injection makes the distribution of remaining oil more complicated, resulting in the problem of difficulty in improving the recovery rate.

[0003] The extraction of oil and gas is the result of the energy drive of oil and gas reservoirs. The evaluation of oil and gas reservoir energy is a basic task in the process of oil and gas extraction. Only by accurately evaluating the energy and drive type of oil and gas reservoir units can more targeted technical countermeasures for oil and gas reservoir development be formulated.

[0004] In the current technology, the traditional evaluation method of the energy status of oil and gas reservoirs often uses two indicators for evaluation, namely, the dimensionless elastic production ratio (Npr) and the formation pressure drop (Dpr) at 1% of the geological reserves, and divides the natural energy of oil and gas reservoirs into four types, namely, I: sufficient, II: relatively sufficient, III: general, and IV: insufficient.

[0005] The above evaluation methods are often applied to developed reservoir units, but cannot be applied to undeveloped reservoir units. Therefore, when evaluating the energy characteristics and driving types of undeveloped reservoir units, necessary methods and means are lacking, especially for carbonate oil and gas reservoirs. This type of reservoir has complex geological conditions, diverse reservoir types, strong heterogeneity, and complex fluid types and distribution. It shows the characteristics of "one well, one reservoir, one policy". Before entering into development, if the reservoir capacity characteristics can be evaluated in alignment, it will play a positive role in a series of oil and gas reservoir development technologies such as the development mode of the oil and gas reservoir, well spacing, well type and well network, injection and production parameters, etc.

[0006] Therefore, there is an urgent need for a natural energy evaluation method for fault-controlled fracture-cavity carbonate reservoirs, so as to solve the problem that the existing energy status evaluation methods of oil and gas reservoirs cannot evaluate undeveloped reservoirs. Summary of the invention

[0007] In order to solve the problems existing in the prior art, the embodiments of this specification provide a method and device for evaluating the natural energy of the formations of fault-controlled fracture-cavity carbonate oil reservoirs, which realizes the evaluation of the natural energy of the formations of undeveloped units in fault-controlled fracture-cavity carbonate oil reservoirs, so as to facilitate the staff to formulate more targeted oil and gas reservoir development technologies, thereby improving the utilization rate of reserves and improving the recovery rate.

[0008] In order to solve any of the above technical problems, the specific technical solutions of this specification are as follows:

[0009] The embodiment of this specification provides a method for evaluating the natural energy of a fault-controlled fracture-cavity carbonate reservoir formation, comprising:

[0010] Obtain the natural energy evaluation indexes of multiple developed wells on developed reservoir block units in the target formation;

[0011] Determine the natural energy rating of the target formation according to the natural energy evaluation indicators of the plurality of developed wells and the actual natural energy conditions of the plurality of developed wells;

[0012] Acquire the seismic reservoir evaluation parameters of the developed wells, and fit the relationship between the seismic reservoir evaluation parameters of the developed wells and the natural energy evaluation indexes of the developed wells;

[0013] Obtain the seismic reservoir evaluation parameters of the undeveloped well on the undeveloped oil reservoir block unit in the target formation, and calculate the natural energy evaluation index of the undeveloped well corresponding to the seismic reservoir evaluation parameters of the undeveloped well according to the relationship, and determine the natural energy situation corresponding to the natural energy evaluation index of the undeveloped well according to the natural energy rating.

[0014] Furthermore, determining the natural energy rating of the target formation according to the natural energy evaluation indicators of the plurality of developed wells and the actual natural energy conditions of the plurality of developed wells further includes:

[0015] Classifying the plurality of developed wells into a plurality of predetermined natural energy levels according to actual natural energy conditions of the plurality of developed wells;

[0016] For each of the predetermined natural energy levels, the corresponding natural energy evaluation index of the developed well is calculated to obtain a natural energy evaluation index threshold corresponding to the predetermined natural energy level;

[0017] The correspondence between the natural energy index threshold and the predetermined natural energy level is used as the natural energy rating.

[0018] Furthermore, fitting the relationship between the seismic reservoir evaluation parameters of the developed wells and the natural energy evaluation indexes of the developed wells further includes:

[0019] Taking the seismic reservoir evaluation parameters of the developed wells as independent variables and the natural energy evaluation indexes of the developed wells as dependent variables;

[0020] The relationship between the independent variable and the dependent variable is fitted by a multiple linear regression fitting algorithm to obtain the relationship equation.

[0021] Furthermore, the natural energy evaluation index includes the pressure drop value of 1% geological reserves and the dimensionless elastic production ratio;

[0022] The seismic reservoir evaluation parameters include fracture depth, fracture zone width and bead length.

[0023] Furthermore, the relationship includes:

[0024] Dpr=a D +b D X1+c D X2+d D X3;

[0025] Npr=a N +b N X1+c N X2+d N X3;

[0026] Where Dpr represents the pressure drop value of 1% geological reserves, Npr represents the dimensionless elastic production ratio, X1 represents the break depth, X2 represents the width of the fracture zone, X3 represents the length of the bead, and a D 、b D 、c Dd D 、a N 、b N 、c N d N Represents the coefficient.

[0027] Furthermore, the step of obtaining the natural energy evaluation index of multiple developed wells in the developed oil reservoir block unit in the target formation further includes:

[0028] Obtaining production characteristic parameters of the developed well;

[0029] The natural energy evaluation index of the developed well is calculated according to the production characteristic parameters of the developed well.

[0030] Furthermore, the production characteristic parameters of the developed wells include: original formation pressure, current formation pressure, current cumulative oil production, geological reserves, crude oil volume coefficient at original pressure, crude oil volume coefficient at current formation pressure, and comprehensive reservoir compressibility coefficient;

[0031] Calculating the natural energy evaluation index of the developed well according to the production characteristic parameters of the developed well further includes:

[0032] Using the formula Calculate the pressure drop value of producing 1% of geological reserves, where Dpr represents the pressure drop value of producing 1% of geological reserves, pi represents the original formation pressure, p represents the current formation pressure, Np represents the current cumulative oil production, and N represents the geological reserves;

[0033] Using the formula The dimensionless elastic production ratio is calculated, wherein Npr represents the dimensionless elastic production ratio, Bo represents the crude oil volume coefficient under the original pressure, Boi represents the crude oil volume coefficient under the current formation pressure, and Ct represents the comprehensive compressibility coefficient of the reservoir.

[0034] On the other hand, the embodiment of this specification also provides a natural energy evaluation device for a fault-controlled fracture-cavity carbonate reservoir formation, comprising:

[0035] A natural energy evaluation index acquisition unit is used to acquire natural energy evaluation indexes of multiple developed wells on developed oil reservoir block units in the target formation;

[0036] A natural energy rating determination unit, used to determine the natural energy rating of the target formation according to the natural energy evaluation indicators of the plurality of developed wells and the actual natural energy conditions of the plurality of developed wells;

[0037] A fitting relationship calculation unit, used for obtaining the seismic reservoir evaluation parameters of the plurality of developed wells, and fitting the relationship between the seismic reservoir evaluation parameters of the plurality of developed wells and the natural energy evaluation indexes of the plurality of developed wells;

[0038] The undeveloped well energy evaluation unit is used to obtain the seismic reservoir evaluation parameters of the undeveloped well on the undeveloped oil reservoir block unit in the target formation, and calculate the natural energy evaluation index of the undeveloped well corresponding to the seismic reservoir evaluation parameters of the undeveloped well according to the relationship, and determine the natural energy situation corresponding to the natural energy evaluation index of the undeveloped well according to the natural energy rating.

[0039] On the other hand, an embodiment of the present specification further provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the above method when executing the computer program.

[0040] Finally, an embodiment of this specification also provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and the computer program implements the above method when executed by a processor.

[0041] Using the embodiment of this specification, first obtain the natural energy evaluation index of multiple developed wells on the developed oil reservoir block unit in the target stratum, and then determine the natural energy rating of the target stratum according to the actual natural energy situation and natural energy index of the developed well, so as to achieve the characterization of reservoir characteristics. Then obtain the seismic reservoir evaluation parameters of the developed well, and establish the matching relationship between the dynamic and static characteristics of the oil and gas reservoir by using the relationship between the seismic reservoir evaluation parameters of multiple developed wells and the natural energy evaluation index of the developed well, so as to predict the production dynamic characteristics and energy characteristics of the undeveloped well, and then determine a more reasonable and effective technical development policy for the undeveloped well, and improve the oil and gas reservoir recovery rate of the undeveloped well. Using the method of the embodiment of this specification to achieve accurate quantitative prediction of the natural energy characteristics of carbonate oil and gas reservoirs can play a more accurate role in the formulation of technical countermeasures for the development of undeveloped oil reservoir units, and has guiding significance for the optimization of the development method of undeveloped oil and gas reservoir units. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the embodiments of this specification or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this specification. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0043] Figure 1It is a schematic diagram of an implementation system of a method for evaluating natural energy of a fault-controlled fracture-cavity carbonate reservoir formation according to an embodiment of this specification;

[0044] Figure 2 It is a schematic diagram of a flow chart of a method for evaluating natural energy of a fault-controlled fracture-cavity carbonate reservoir formation according to an embodiment of this specification;

[0045] Figure 3 The steps of determining the natural energy rating of the target formation in the embodiment of this specification are shown;

[0046] Figure 4 It shows the steps of obtaining the natural energy evaluation index of multiple developed wells on the developed oil reservoir block unit in the target formation in the embodiment of this specification;

[0047] Figure 5 The figure shows a schematic diagram of the structure of a natural energy evaluation device for a fault-controlled fracture-cavity carbonate reservoir according to an embodiment of the present specification;

[0048] Figure 6 The figure shows a schematic diagram of the structure of a computer device according to an embodiment of the present specification.

[0049]

Description of the accompanying drawings

[0050] 101. Terminal;

[0051] 102. Server;

[0052] 501. Natural energy evaluation index acquisition unit;

[0053] 502. Natural energy rating determination unit;

[0054] 503, fitting relation calculation unit;

[0055] 504. Undeveloped well energy evaluation unit;

[0056] 602. Computer equipment;

[0057] 604, processor;

[0058] 606. Memory;

[0059] 608, driving mechanism;

[0060] 610, input / output module;

[0061] 612. Input devices;

[0062] 614. Output devices;

[0063] 616. Presentation equipment;

[0064] 618. Graphical user interface;

[0065] 620, network interface;

[0066] 622, communication link;

[0067] 624. Communication bus. DETAILED DESCRIPTION

[0068] The following will be combined with the drawings in the embodiments of this specification to clearly and completely describe the technical solutions in the embodiments of this specification. Obviously, the described embodiments are only part of the embodiments of this specification, not all of the embodiments. Based on the embodiments in this specification, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this specification.

[0069] It should be noted that the terms "first", "second", etc. in the description and claims of this specification and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of this specification described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, device, product or equipment that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or equipment.

[0070] It should be noted that the steps shown in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and that, although a logical order is shown in the flowcharts, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0071] like Figure 1Shown is a schematic diagram of an implementation system of a method for evaluating natural energy of a fault-controlled fracture-cavity carbonate reservoir formation according to an embodiment of the present specification, which may include: a terminal 101 and a server 102. The terminal 101 and the server 102 communicate with each other via a network, and the network may include a local area network (LAN), a wide area network (WAN), the Internet or a combination thereof, and is connected to a website, a user device (such as a computing device) and a back-end system. The terminal 101 can be a sensor or a data acquisition system, which is used to collect data of multiple developed wells on the developed oil reservoir block unit in the target formation, and then send the collected data to the server 102. The server 102 determines the natural energy rating of the target formation and the dynamic and static characteristics matching relationship of the oil and gas reservoir based on the data of the developed wells. In addition, the terminal 101 can also send the data of the undeveloped wells in the target formation to the server 102. The server 102 determines the natural energy rating of the undeveloped well based on the data of the undeveloped well and the natural energy rating and dynamic and static characteristics matching relationship established using the data of the developed wells, and sends the natural energy rating of the undeveloped well to the terminal 101, thereby providing it to the staff. Optionally, the processor can be a node of a cloud computing system (not shown in the figure), or each processor can be a separate cloud computing system, including multiple computers interconnected by a network and working as a distributed processing system.

[0072] In addition, it should be noted that Figure 1 What is shown is only one application environment provided by the present disclosure. In actual application, other application scenarios may also be included, and this specification does not limit them.

[0073] In order to solve the problems existing in the prior art, the embodiments of this specification provide a method for evaluating the natural energy of the formations of fault-controlled fracture-cavity carbonate oil reservoirs, which realizes the evaluation of the natural energy of the formations of undeveloped units in fault-controlled fracture-cavity carbonate oil reservoirs, so as to facilitate the staff to formulate more targeted oil and gas reservoir development technologies, thereby improving the utilization rate of reserves and improving the recovery rate. Figure 2 The embodiment of this specification shows a natural energy evaluation process of a fault-controlled fracture-cavity carbonate reservoir formation, which is a process of natural energy rating of undeveloped wells based on data from developed wells, but it may include more or fewer operating steps based on conventional or non-creative labor. The sequence of steps listed in the embodiment is only one way of executing the steps among many, and does not represent the only execution sequence. When the system or device product is actually executed, it can be executed in sequence or in parallel according to the method shown in the embodiment or the accompanying drawings. Specifically, Figure 2 As shown, the method may be executed by the server 102, and may include:

[0074] Step 201: obtaining natural energy evaluation indicators of multiple developed wells in developed oil reservoir block units in a target formation;

[0075] Step 202: Determine the natural energy rating of the target formation according to the natural energy evaluation indicators of the plurality of developed wells and the actual natural energy conditions of the plurality of developed wells;

[0076] Step 203: obtaining seismic reservoir evaluation parameters of the plurality of developed wells, and fitting the relationship between the seismic reservoir evaluation parameters of the plurality of developed wells and the natural energy evaluation indexes of the plurality of developed wells;

[0077] Step 204: Obtain the seismic reservoir evaluation parameters of the undeveloped wells on the undeveloped oil reservoir block unit in the target formation, and calculate the natural energy evaluation index of the undeveloped well corresponding to the seismic reservoir evaluation parameters of the undeveloped well according to the relationship, and determine the natural energy situation corresponding to the natural energy evaluation index of the undeveloped well according to the natural energy rating.

[0078] Through the method of the embodiment of this specification, the natural energy evaluation index of multiple developed wells on the developed oil reservoir block unit in the target stratum is first obtained, and then the natural energy rating of the target stratum is determined according to the actual natural energy situation of the developed well and the natural energy index, so as to achieve the characterization of the reservoir characteristics. Then, the seismic reservoir evaluation parameters of the developed wells are obtained, and the relationship between the seismic reservoir evaluation parameters of multiple developed wells and the natural energy evaluation index of the developed wells is fitted, and the matching relationship between the dynamic and static characteristics of the oil and gas reservoir is established, so as to predict the production dynamic characteristics and energy characteristics of the undeveloped wells, and then determine a more reasonable and effective technical development policy for the undeveloped wells, and improve the oil and gas reservoir recovery rate of the undeveloped wells. The method of the embodiment of this specification is used to realize the accurate quantitative prediction of the natural energy characteristics of carbonate oil and gas reservoirs, which can play a more accurate role in the formulation of technical countermeasures for the development of undeveloped oil reservoir units, and has guiding significance for the optimization of the development method of undeveloped oil and gas reservoir units.

[0079] In the embodiments of this specification, the natural energy of the reservoir includes gas cap gas drive, water pressure drive, elastic drive, solution gas drive, gravity drive, etc. There are currently two commonly used indicators for evaluating the natural energy of the reservoir. One is the dimensionless elastic energy ratio, and the other is the average formation pressure drop value after 1% geological reserves are produced. The embodiments of this specification can use these two indicators to conduct qualitative and quantitative evaluation of the natural energy of the developed wells, that is, determine the natural energy rating of the target formation based on the natural energy evaluation indicators of multiple developed wells and the actual natural energy conditions of multiple developed wells.

[0080] However, because the natural energy evaluation index needs to be calculated based on the data of developed wells, it is impossible to directly calculate the natural energy evaluation index for undeveloped wells. Therefore, it is impossible to determine the natural energy rating of the undeveloped wells, resulting in the staff being unable to specify more targeted oil and gas reservoir development technologies and unable to improve the recovery rate.

[0081] Therefore, in the embodiment of this specification, a relationship between the natural energy evaluation index of the developed well and the seismic reservoir evaluation parameter is established. Optionally, the natural energy evaluation index of the developed well and the seismic reservoir evaluation parameter are fitted to obtain the relationship between the two. Then, for the undeveloped well, its seismic reservoir evaluation parameter is obtained, and the natural energy evaluation index of the undeveloped well is evaluated using the fitted relationship, so as to determine the natural energy situation of the undeveloped well using the evaluated natural energy evaluation index and the established natural energy rating.

[0082] In the embodiments of this specification, the seismic reservoir evaluation parameters can be obtained through seismic data, such as seismic profiles, and the seismic reservoir evaluation parameters in the embodiments of this specification may include the depth of the fracture penetration, the abnormal reflection width of the fracture zone, and the "beaded" reflection length. These parameters can reflect the size of the reservoir to a certain extent, as well as the positive correlation between the reservoir size and natural energy.

[0083] According to one embodiment of this specification, Figure 3 As shown, determining the natural energy rating of the target formation according to the natural energy evaluation indicators of the plurality of developed wells and the actual natural energy conditions of the plurality of developed wells further includes:

[0084] Step 301: Classifying the plurality of developed wells into a plurality of predetermined natural energy levels according to actual natural energy conditions of the plurality of developed wells;

[0085] Step 302: for each of the predetermined natural energy levels, calculating the corresponding natural energy evaluation index of the developed well to obtain a natural energy evaluation index threshold corresponding to the predetermined natural energy level;

[0086] Step 303: The corresponding relationship between the natural energy index threshold and the predetermined natural energy level is used as the natural energy rating.

[0087] In the embodiment of the present specification, in order to perform natural energy rating on developed wells, first, multiple developed wells are divided into multiple predetermined natural energy levels according to their actual natural energy conditions, and then for each predetermined natural energy level, the natural energy evaluation index of the developed well corresponding to it is calculated to obtain the natural energy evaluation index threshold corresponding to the predetermined natural energy level. For example, according to the natural energy evaluation index of the developed well, the upper and lower limits of the index corresponding to the predetermined natural energy level are calculated as the index threshold. Finally, the corresponding relationship between the natural energy index threshold and the natural energy level is used as the natural energy rating.

[0088] For example, the natural energy rating may be as shown in Table 1:

[0089] Table 1 Natural energy rating

[0090]

[0091] In the embodiment of this specification, the natural energy evaluation index includes two items, namely, the pressure drop value (Dpr) after producing 1% of geological reserves and the dimensionless elastic production ratio (Npr). When determining the natural energy of the reservoir of an undeveloped well, it is necessary to combine the Dpr and Npr of the undeveloped well to determine the natural energy level of the reservoir to which the undeveloped well belongs. Therefore, when fitting the relationship between the natural energy evaluation index of the reservoir and the seismic reservoir evaluation parameters, it is necessary to fit the relationship between Dpr and the seismic reservoir evaluation parameters and the relationship between Npr and the seismic reservoir evaluation parameters, respectively, so as to estimate Dpr and Npr respectively according to the seismic reservoir evaluation parameters of the undeveloped well.

[0092] Therefore, according to one embodiment of the present specification, the relationship includes:

[0093] Dpr=a D +b D X1+c D X2+d D X3;

[0094] Npr=a N +b N X1+c N X2+d N X3;

[0095] Where Dpr represents the pressure drop value of 1% geological reserves, Npr represents the dimensionless elastic production ratio, X1 represents the break depth, X2 represents the width of the fracture zone, X3 represents the length of the bead, and a D 、b D 、c D ,d D 、a N 、b N 、cN d N Represents the coefficient.

[0096] Specifically, the above relationship can be fitted using SPSS mathematical statistical analysis software:

[0097] Firstly, the independent variables of fracture depth X1, fracture zone width X2 and bead length X3 were input into SPSS mathematical statistical analysis software, and the dependent variables of 1% geological reserve pressure drop value Dpr and dimensionless elastic production ratio Npr were input;

[0098] Then select the multivariate linear regression fitting method to establish the above relationship between the independent variables X1, X2, X3 and the dependent variables Dpr and Npr;

[0099] Finally, we get the fitting parameter a D 、b D 、c D d D 、a N 、b N 、c N d N , determine the relationship between Dpr and X1, X2, X3, and the relationship between Npr and X1, X2, X3.

[0100] The size of the natural energy of the reservoir mainly depends on two factors: one is the scale of the reservoir, and the other is the filling intensity. The larger the reservoir scale and the stronger the filling intensity, the more abundant the natural energy. For fault-controlled fracture-cavity carbonate reservoirs, it is simpler and faster to use geophysical methods to obtain parameters related to the scale and filling intensity of the reservoir based on high-quality three-dimensional data. Compared with other parameters, the three parameters of fault penetration depth, fracture zone width and bead length are easier to obtain and less affected by human factors. At the same time, the greater the fault penetration depth, the better the fracture permeability, and the more conducive to oil and gas filling. Therefore, the parameter of fault penetration depth can reflect the filling intensity to a certain extent. The reservoir of fault-controlled fracture-cavity carbonate reservoirs is mainly controlled by fracture fragmentation and dissolution. The larger the width of the fracture zone indicates the higher the degree of fracture fragmentation, and the longer the bead length indicates the stronger the dissolution. The two parameters can reflect the scale of the reservoir. Therefore, the selection of the three parameters of fault penetration depth, fracture zone width and bead length to evaluate the natural energy of fault-controlled fracture-cavity carbonate reservoirs has the advantages of simple operation and accurate calculation.

[0101] In some other embodiments of the present specification, the step of fitting the relationship between Dpr and Npr also includes: calculating the difference between the actual value and the fitted value of the natural energy evaluation index, and checking the reliability of the fitted relationship based on the difference.

[0102] For example, the fitting data table of the natural energy evaluation index and the seismic reservoir evaluation parameters of each developed well can be shown in Table 2:

[0103] Table 2 Fitting data of natural energy evaluation indexes and seismic reservoir evaluation parameters of developed wells

[0104]

[0105] The constructed relationship is:

[0106] Dpr=17.6131+0.01767X1-0.02705X2-0.01773X3

[0107] Npr=-1.3967+0.010236X1-0.00292X2-0.00141X3

[0108] The natural energy evaluation determined by the seismic reservoir evaluation parameters of each undeveloped well is shown in Table 3:

[0109] Table 3 Determination of natural energy evaluation of seismic reservoir evaluation parameters for each well of undeveloped wells

[0110]

[0111] According to one embodiment of this specification, Figure 4 As shown, the step of obtaining the natural energy evaluation index of multiple developed wells on the developed reservoir block unit in the target formation further includes:

[0112] Step 401: Obtaining production characteristic parameters of the developed well;

[0113] Step 402: Calculate the natural energy evaluation index of the developed well according to the production characteristic parameters of the developed well.

[0114] In the embodiments of this specification, the production characteristic parameters of the developed wells include: original formation pressure, current formation pressure, current cumulative oil production, geological reserves, crude oil volume coefficient at original pressure, crude oil volume coefficient at current formation pressure, and comprehensive reservoir compressibility coefficient;

[0115] Calculating the natural energy evaluation index of the developed well according to the production characteristic parameters of the developed well further includes:

[0116] Using the formula Calculate the pressure drop value of producing 1% of geological reserves, where Dpr represents the pressure drop value of producing 1% of geological reserves, pi represents the original formation pressure, p represents the current formation pressure, Np represents the current cumulative oil production, and N represents the geological reserves;

[0117] Using the formula The dimensionless elastic production ratio is calculated, wherein Npr represents the dimensionless elastic production ratio, Bo represents the crude oil volume coefficient under the original pressure, Boi represents the crude oil volume coefficient under the current formation pressure, and Ct represents the comprehensive compressibility coefficient of the reservoir.

[0118] For example, the natural energy classification results of the developed wells 1-7 shown in Table 2 can be shown in Table 4:

[0119] Table 4 Natural energy classification results of developed wells

[0120]

[0121] Based on the same inventive concept, the embodiment of this specification also provides a natural energy evaluation device for fault-controlled fracture-cavity carbonate reservoir formations, such as Figure 5 As shown, including:

[0122] The natural energy evaluation index acquisition unit 501 is used to acquire the natural energy evaluation indexes of multiple developed wells on the developed oil reservoir block unit in the target formation;

[0123] A natural energy rating determination unit 502 is used to determine the natural energy rating of the target formation according to the natural energy evaluation indicators of the plurality of developed wells and the actual natural energy conditions of the plurality of developed wells;

[0124] A fitting relationship calculation unit 503 is used to obtain the seismic reservoir evaluation parameters of the developed wells, and fit the relationship between the seismic reservoir evaluation parameters of the developed wells and the natural energy evaluation indexes of the developed wells;

[0125] The undeveloped well energy evaluation unit 504 is used to obtain the seismic reservoir evaluation parameters of the undeveloped well on the undeveloped oil reservoir block unit in the target formation, and calculate the natural energy evaluation index of the undeveloped well corresponding to the seismic reservoir evaluation parameters of the undeveloped well according to the relationship, and determine the natural energy situation corresponding to the natural energy evaluation index of the undeveloped well according to the natural energy rating.

[0126] The beneficial effects obtained by the above-mentioned device are consistent with the beneficial effects obtained by the above-mentioned method, and will not be described in detail in the embodiments of this specification.

[0127] like Figure 6As shown, a computer device provided in an embodiment of the present invention, the apparatus in this article can be a computer device in this embodiment, executing the above method in this article, the computer device 602 may include one or more processors 604, such as one or more central processing units (CPUs), each processing unit can implement one or more hardware threads. The computer device 602 may also include any memory 606, which is used to store any kind of information such as code, settings, data, etc. Non-limiting, for example, the memory 606 may include any one or more combinations of the following: any type of RAM, any type of ROM, flash memory device, hard disk, optical disk, etc. More generally, any memory can use any technology to store information. Further, any memory can provide volatile or non-volatile retention of information. Further, any memory can represent a fixed or removable component of the computer device 602. In one case, when the processor 604 executes an associated instruction stored in any memory or a combination of memories, the computer device 602 can perform any operation of the associated instruction. The computer device 602 also includes one or more drive mechanisms 608 for interacting with any memory, such as a hard disk drive mechanism, an optical disk drive mechanism, etc.

[0128] The computer device 602 may also include an input / output module 610 (I / O) for receiving various inputs (via input devices 612) and for providing various outputs (via output devices 614). A specific output mechanism may include a presentation device 616 and an associated graphical user interface (GUI) 618. In other embodiments, the input / output module 610 (I / O), the input device 612, and the output device 614 may not be included, and the computer device 602 may be used as a computer device in a network. The computer device 602 may also include one or more network interfaces 620 for exchanging data with other devices via one or more communication links 622. One or more communication buses 624 couple the components described above together.

[0129] The communication link 622 may be implemented in any manner, for example, through a local area network, a wide area network (e.g., the Internet), a point-to-point connection, etc., or any combination thereof. The communication link 622 may include any combination of hardwired links, wireless links, routers, gateway functions, name servers, etc. governed by any protocol or combination of protocols.

[0130] The embodiments of the present specification also provide a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and the computer program implements the above method when executed by a processor.

[0131] The embodiments of the present specification also provide a computer-readable instruction, wherein when a processor executes the instruction, the program therein causes the processor to execute the above method.

[0132] It should be understood that in the various embodiments of this specification, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this specification.

[0133] It should also be understood that in the embodiments of this specification, the term "and / or" is only a description of the association relationship of the associated objects, indicating that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this specification generally indicates that the associated objects before and after are in an "or" relationship.

[0134] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed in this specification can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in the above description according to function. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this specification.

[0135] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0136] In the several embodiments provided in this specification, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or units, or it can be an electrical, mechanical or other form of connection.

[0137] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the embodiments of this specification.

[0138] In addition, each functional unit in each embodiment of this specification may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0139] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this specification is essentially or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of this specification. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program codes.

[0140] Specific embodiments are used in this specification to illustrate the principles and implementation methods of this specification. The description of the above embodiments is only used to help understand the methods and core ideas of this specification. At the same time, for those skilled in the art, according to the ideas of this specification, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on this specification.

Claims

1. A method for evaluating the natural energy of a fault-controlled fracture-cavity carbonate reservoir, characterized in that: include: Obtain the natural energy evaluation indexes of multiple developed wells on developed reservoir block units in the target formation; Determine the natural energy rating of the target formation according to the natural energy evaluation indicators of the plurality of developed wells and the actual natural energy conditions of the plurality of developed wells; Acquire the seismic reservoir evaluation parameters of the developed wells, and fit the relationship between the seismic reservoir evaluation parameters of the developed wells and the natural energy evaluation indexes of the developed wells; Obtain the seismic reservoir evaluation parameters of the undeveloped well on the undeveloped oil reservoir block unit in the target formation, and calculate the natural energy evaluation index of the undeveloped well corresponding to the seismic reservoir evaluation parameters of the undeveloped well according to the relationship, and determine the natural energy situation corresponding to the natural energy evaluation index of the undeveloped well according to the natural energy rating.

2. The method according to claim 1, characterized in that Determining the natural energy rating of the target formation according to the natural energy evaluation indicators of the plurality of developed wells and the actual natural energy conditions of the plurality of developed wells further comprises: Classifying the plurality of developed wells into a plurality of predetermined natural energy levels according to actual natural energy conditions of the plurality of developed wells; For each of the predetermined natural energy levels, the corresponding natural energy evaluation index of the developed well is calculated to obtain a natural energy evaluation index threshold corresponding to the predetermined natural energy level; The correspondence between the natural energy index threshold and the predetermined natural energy level is used as the natural energy rating.

3. The method according to claim 1, characterized in that Fitting the relationship between the seismic reservoir evaluation parameters of the developed wells and the natural energy evaluation indexes of the developed wells further includes: Taking the seismic reservoir evaluation parameters of the developed wells as independent variables and the natural energy evaluation indexes of the developed wells as dependent variables; The relationship between the independent variable and the dependent variable is fitted by a multiple linear regression fitting algorithm to obtain the relationship equation.

4. The method according to claim 3, characterized in that The natural energy evaluation indexes include the pressure drop value of 1% geological reserves and the dimensionless elastic production ratio; The seismic reservoir evaluation parameters include fracture depth, fracture zone width and bead length.

5. The method according to claim 4, characterized in that The relationship includes: Dpr=a D +b D X1+c D X2+d D X3; Npr=a N +b N X1+c N X2+d N X3; Where Dpr represents the pressure drop value of 1% geological reserves, Npr represents the dimensionless elastic production ratio, X1 represents the break depth, X2 represents the width of the fracture zone, X3 represents the length of the bead, and a D 、b D 、c D d D 、a N 、b N 、c N d N Represents the coefficient.

6. The method according to claim 4, characterized in that The step of obtaining the natural energy evaluation index of multiple developed wells on the developed reservoir block unit in the target formation further includes: Acquiring production characteristic parameters of the developed well; The natural energy evaluation index of the developed well is calculated according to the production characteristic parameters of the developed well.

7. The method according to claim 6, characterized in that The production characteristic parameters of the developed wells include: original formation pressure, current formation pressure, current cumulative oil production, geological reserves, crude oil volume coefficient at original pressure, crude oil volume coefficient at current formation pressure, and comprehensive reservoir compressibility coefficient; Calculating the natural energy evaluation index of the developed well according to the production characteristic parameters of the developed well further includes: Using the formula Calculate the pressure drop value of producing 1% of geological reserves, where Dpr represents the pressure drop value of producing 1% of geological reserves, pi represents the original formation pressure, p represents the current formation pressure, Np represents the current cumulative oil production, and N represents the geological reserves; Using the formula The dimensionless elastic production ratio is calculated, wherein Npr represents the dimensionless elastic production ratio, Bo represents the crude oil volume coefficient under the original pressure, Boi represents the crude oil volume coefficient under the current formation pressure, and Ct represents the comprehensive compressibility coefficient of the reservoir.

8. A natural energy evaluation device for fault-controlled fracture-cavity carbonate reservoir formation, characterized in that: include: A natural energy evaluation index acquisition unit is used to acquire natural energy evaluation indexes of multiple developed wells on developed oil reservoir block units in the target formation; A natural energy rating determination unit, used to determine the natural energy rating of the target formation according to the natural energy evaluation indicators of the plurality of developed wells and the actual natural energy conditions of the plurality of developed wells; A fitting relationship calculation unit, used for obtaining the seismic reservoir evaluation parameters of the plurality of developed wells, and fitting the relationship between the seismic reservoir evaluation parameters of the plurality of developed wells and the natural energy evaluation indexes of the plurality of developed wells; The undeveloped well energy evaluation unit is used to obtain the seismic reservoir evaluation parameters of the undeveloped well on the undeveloped oil reservoir block unit in the target formation, and calculate the natural energy evaluation index of the undeveloped well corresponding to the seismic reservoir evaluation parameters of the undeveloped well according to the relationship, and determine the natural energy situation corresponding to the natural energy evaluation index of the undeveloped well according to the natural energy rating.

9. A computer device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the method according to any one of claims 1 to 7 is implemented.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the method according to any one of claims 1 to 7 is implemented.

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