CN109270578B - Rolling development method for low-grade oil reservoir in shoal and shallow sea - Google Patents

Abstract

The invention provides a rolling development method of a low-grade oil reservoir in shoal and shoal sea, which comprises the following steps: step 1, developing fine oil reservoir description according to exploratory well data, and clearing reservoir development rules and reserve scales; step 2, carrying out well-to-seismic combination, and depicting an interpretation structure and a fault by using a three-dimensional man-machine interaction interpretation technology and a coherent body seismic attribute processing technology; step 3, formulating a reasonable drilling sequence, simulating a well track, and adjusting and deploying the next well position after the new well is designed and drilled; step 4, combining newly completed well data, deploying an oil reservoir evaluation well for the unknown block, and synchronously implementing the oil reservoir evaluation well and the productivity building well; and the unknown block reserves are implemented, and the whole capacity scale of the scheme is ensured. The rolling development method of the low-grade oil reservoir in the shoal and shallow sea fully considers the characteristic of rapid distribution change of the underground reservoir of the low-grade oil reservoir, breaks through reserve loss caused by platform limitation, has better operability, is innovative and practical, and is beneficial to popularization.

Description

Rolling development method for low-grade oil reservoir in shoal and shallow sea

Technical Field

The invention relates to the field of petroleum development geology fine reservoir description research, in particular to a rolling development method of a shoal and shallow sea low-grade reservoir.

Background

Along with the deepening of the exploration and development stage of the oil field, the whole oil field is difficult to excavate and submerge, and the low-grade oil reservoir is continuously used for realizing resource replacement, hard and stable yield of crude oil. The low-grade oil reservoir has the characteristics of being few, poor, thin and small, and the resource grade is low. The method has four characteristics from the oil reservoir perspective: the first 'few' means that the exploratory well is few, the oil reservoir characteristics are not known, and the reserve scale is not realized; secondly, the problems of poor seismic quality and great difficulty in reservoir prediction are solved, the large sand body spreading characteristics can only be realized, and the thickness of a common seismic inversion reservoir in a new beach shallow sea area cannot meet the requirements of scheme establishment; the third is thin, the oil layer is mostly thin interbed and has poor transverse continuity, the average thickness is only a few meters, and the development risk is large; fourth, "small", the fault develops systematically, the target layer is often cut by the fault into many small fault blocks, some secondary small faults develop inside the fault blocks. Secondly, in the face of the characteristics of shallow water depth and small fault block heavy oil reservoirs in the sea area of the research area, a 'sea oil land mining' mode is generally required to be adopted in scheme design, namely before a well is opened, an access and an artificial island are required to be repaired, and a scheme design new well is required to be implemented from one platform, so that the development risk is further increased. In order to utilize resources to the maximum extent and reduce risks, a new evaluation method is required to judge the oil reservoir reserves and the capacity scale. Therefore, a novel rolling development method for the low-grade oil reservoir in the shoal and shallow sea is invented, and the technical problems are solved.

Disclosure of Invention

The invention aims to provide a rolling development method for a beach shallow sea low-grade oil reservoir, which solves the problem that the productivity is reduced due to errors of an actual reservoir and a predicted reservoir which possibly occur in the oil reservoir development process and achieves the purpose of efficient development of a low-grade oil field.

The object of the invention can be achieved by the following technical measures: the rolling development method of the low-grade oil reservoir in the shoal and shallow sea comprises the following steps: step 1, developing fine oil reservoir description according to exploratory well data, and clearing reservoir development rules and reserve scales; step 2, carrying out well-to-seismic combination, and depicting an interpretation structure and a fault by using a three-dimensional man-machine interaction interpretation technology and a coherent body seismic attribute processing technology; step 3, formulating a reasonable drilling sequence, simulating a well track, and adjusting and deploying the next well position after the new well is designed and drilled; and 4, deploying an oil reservoir evaluation well for the unknown block, synchronously implementing with the oil reservoir evaluation well, implementing the reserve of the unknown block, and ensuring the scale of the whole productivity.

The object of the invention can also be achieved by the following technical measures:

in the step 1, according to the data of the drilled exploratory well, combining with core observation, according to the characteristics of deposition cycle in the longitudinal direction, combining with lithology and electrical characteristics, dividing a sand layer group into a target section of a research area, and dividing an oil-containing sand group into small layers and a single sand body on the basis; analyzing the development characteristics of a reservoir plane by applying analysis and logging data, determining the direction and the law of a material source, analyzing oil reservoir control factors, implementing the scale of reserves, carrying out the primary conceptual design of a capacity scheme, carrying out oil testing and production trial on a completely drilled development and evaluation well, and clearly building a production position.

In step 2, three-dimensional seismic data are applied to perform seismic synthetic record calibration on the completed well, and the seismic synthetic record calibration and wavelet extraction are performed interactively; during calibration, firstly selecting Rake wavelets as synthetic seismic records, performing seismic calibration to a certain degree, then cutting a time window near a target layer, obtaining a constant-phase initial wavelet from seismic data by a multi-channel seismic record autocorrelation statistical method to obtain synthetic records, and then extracting the wavelets and then calibrating until the synthetic seismic records with higher correlation coefficients are obtained; determining the depth relationship, finely constructing and explaining by using a three-dimensional man-machine interaction interpretation technology, meanwhile, highlighting information related to the fault in the three-dimensional seismic body by combining seismic attribute processing technologies such as coherent bodies and the like, identifying and explaining the fault, and completing a structural diagram of a target layer.

In the step 3, in the implementation process, a control well is determined to be drilled first, the reserve scale is controlled integrally, the real-time tracking is carried out, the adjusting thought is analyzed in time, a reasonable drilling sequence is formulated, the well track is simulated, and after a new well is designed and drilled, the change of the structure and the reservoir is analyzed in the plane and the longitudinal direction by combining the well completion data at the first time, the next well position is adjusted and deployed in time, and the scheme of one well is realized.

In step 3, firstly, plan well position deployment is carried out from the angles of geology, earthquake and oil reservoir respectively, well tracks are designed, well body structures are optimized, reasonable well drilling sequences are formulated on the basis, and single well design is completed; secondly, in the implementation process, the reservoir stratum re-recognition is carried out by performing drilling and drilling completion tracking, developing stratum comparison, structure and reservoir stratum research by combining logging and logging data; and finally, adjusting and deploying subsequent well positions according to the reservoir change condition.

In step 4, with continuous drilling of new wells, reservoir and oil reservoir characteristics are researched, oil reservoir evaluation wells are deployed on the unknown blocks, and are synchronously implemented with the oil reservoir evaluation wells, so that the reserves of the unknown blocks are implemented; the reduction of the number of designed wells caused by the deterioration of a reservoir layer in the drilling process is avoided, and the whole capacity scale of the scheme is ensured.

The rolling development method for the low-grade oil reservoir in the shoal and shallow sea is a determined rolling development method aiming at a block which influences the development effect because the design productivity is reduced due to reservoir change in the development process of the low-grade oil reservoir. The method combines the low-grade oil reservoir rolling evaluation development of earthquake, well logging and geological research, fully considers the characteristic of rapid distribution change of the underground reservoir of the low-grade oil reservoir, breaks through the reserve loss caused by the limitation of a platform, and compiles an implementation flow. The method is applied to 5 Qingdong blocks in the oilfield of Qiandong and 255 Chengjiang oilfield, wherein the 5 Chendong blocks are used for drilling 61 new wells, the drilling success rate is 100 percent, the average single well drilling meets the oil layer by 24.1m, the found reserve is reported to 1108 multiplied by 10 million tons, and the new production capacity is built; the Chengjiang north is 255 blocks, 5 new wells are drilled, the drilling success rate is 100%, the ascertained reserves are reported to be 129.76 ten thousand tons, and the newly-built capacity is 2.4 ten thousand tons; provides technical support for the efficient development of the beach shallow sea oil field.

Drawings

FIG. 1 is a diagram of reservoir evaluation well deployment in accordance with an embodiment of the present invention;

FIG. 2 is a flow chart of a well-seismic reservoir prediction process according to an embodiment of the present invention;

FIG. 3 is a comparison of frequency boosting front and rear seismic sections in an embodiment of the invention;

FIG. 4 is a flow diagram of an embodiment of the present invention implementing tracking;

FIG. 5 is a diagram of a rig deployment in an embodiment of the present invention;

FIG. 6 is a diagram of the deployment of capacity building wells and reservoir evaluation wells in accordance with an embodiment of the present invention;

FIG. 7 is a three-dimensional view of a well trajectory after completion of drilling in accordance with an embodiment of the present invention;

fig. 8 is a flowchart of an embodiment of the rolling development method for a shoal shallow sea low-grade oil reservoir of the present invention.

Detailed Description

In order to make the aforementioned and other objects, features and advantages of the present invention comprehensible, preferred embodiments accompanied with figures are described in detail below.

As shown in fig. 8, fig. 8 is a flowchart of the rolling development method of the low-grade oil reservoir in the shallow sea.

Step 101, developing fine oil reservoir description according to exploratory well data, figuring out reservoir development rules and reserve scale, and carrying out primary conceptual design of a capacity scheme to clarify a production formation area;

according to the data of the drilled exploration well, combining with core observation, according to the characteristics of deposition cycle in the longitudinal direction, combining with lithology and electrical characteristics, dividing a sand layer group into a target section of a research area, and dividing an oil-bearing sand group into small layers and single sand bodies on the basis. Analyzing the development characteristics of a reservoir plane by applying data such as analysis and test, well logging and the like, determining the direction and the law of a material source, analyzing oil reservoir control factors, implementing the scale of reserves, carrying out the preliminary conceptual design of a capacity scheme, carrying out oil testing and production trial on a completely drilled development and evaluation well, and clearly building a production position.

102, developing well-seismic combination, and depicting an interpretation structure and a fault by using a three-dimensional man-machine interaction interpretation technology and a coherent body seismic attribute processing technology;

and (3) applying three-dimensional seismic data to perform seismic synthetic record calibration on the completed well, wherein the seismic synthetic record calibration and wavelet extraction are performed interactively. During calibration, a Rake wavelet is selected to be used as a synthetic seismic record, a certain degree of seismic calibration is carried out, then a time window is cut near a target layer, a constant-phase initial wavelet is obtained from seismic data through a multi-channel seismic record autocorrelation statistical method to obtain a synthetic record, and then the wavelet is extracted and calibrated until the synthetic seismic record with a higher correlation coefficient is obtained. Determining the depth relationship, finely constructing and explaining by using a three-dimensional man-machine interaction interpretation technology, meanwhile, highlighting information related to the fault in the three-dimensional seismic body by combining seismic attribute processing technologies such as coherent bodies and the like, identifying and explaining the fault, and completing a structural diagram of a target layer.

103, in the implementation process, determining a' control well drilling first and integrally controlling the reserve scale by using a rolling implementation principle; the concept of real-time tracking and timely analysis and adjustment is adopted, a reasonable drilling sequence is formulated, well tracks are simulated, and after a new well is designed and drilled, well completion data are combined at the first time, the changes of structures and reservoirs are analyzed in the plane and the longitudinal direction, the next well position is timely adjusted and deployed, and a first well-one scheme is realized. In one embodiment, firstly, plan well position deployment is carried out from the angles of geology, earthquake and oil reservoir respectively, well tracks are designed, well body structures are optimized, a reasonable drilling sequence is formulated on the basis, and single well design is completed; secondly, in the implementation process, the reservoir stratum re-recognition is carried out by performing drilling and drilling completion tracking, developing stratum comparison, structure and reservoir stratum research by combining logging and logging data; and finally, adjusting and deploying subsequent well positions according to the reservoir change condition.

And step 104, continuously drilling a new well, researching the characteristics of the reservoir and the oil deposit, deploying an oil deposit evaluation well for the unknown block, realizing synchronous implementation of the productivity building well and the oil deposit evaluation well, and ensuring the productivity scale.

In an embodiment to which the present invention is applied, the following implementation is included.

(1) FIG. 1 is a diagram of developing and evaluating wells deployed according to a technical flow chart, trial production is carried out, a reservoir is further implemented, and the development concept design capacity is 23 million tons, and FIG. 1 is a diagram of dividing a sand layer group into a target section of a research area according to data of drilled exploratory wells (qd5-2, qd5-7 and qd5-1c) by combining rock core observation and longitudinal deposition cycle characteristics and lithology and electrical characteristics, and dividing an oil-containing sand group into small layers and single sand bodies on the basis of the sand layer group, applying data such as assay analysis and well logging, analyzing planar development characteristics of the reservoir, determining the direction and the rule of a source, analyzing oil deposit control factors, implementing the storage scale, carrying out the capacity scheme preliminary concept design, designing, developing and evaluating wells 5 mouths, drilling oil-meeting layers uniformly, and carrying out trial production on the drilled development and evaluating wells, wherein the production of the trial production single wells is 18-58 t/d, and the implementation storage capacity is 1943 × 10⁴t, design capacity 23 × 10⁴t。

(2) The seismic axis reflection of the target interval is strong or weak, the target interval is broken, the transverse continuity is poor, and certain difficulty is caused to fault and reservoir identification. Thus, according to the division result of the well stratum of the study area, the three-dimensional seismic data of the area is applied, as shown in fig. 2, amplitude-preserving and frequency-increasing processing is firstly carried out, on the basis, seismic synthetic record calibration is carried out, and the seismic synthetic record calibration and wavelet extraction are carried out interactively, so that synthetic seismic records with higher correlation coefficients are obtained. In the synthetic seismic recording, a single well and a multi-well combined calibration are adopted. And single well calibration, which is combined with a seismic standard reflecting layer for calibration, performs initial calibration under the guidance of the Dongying velocity, and enhances the analysis of geology, earthquake, well logging and the like, thereby ensuring accurate and reliable calibration results. Multi-well calibration: the seismic record and the synthetic record have consistent waveform characteristics, the same geological phenomenon and the logging response are consistent, the time-depth relation of wells in the same region is consistent, and the calibration results are consistent on the seismic well-connecting section. Meanwhile, the method combines seismic attribute processing technologies such as variance body and coherent body attribute analysis, highlights the relationship between the three-dimensional seismic body and the fault, finely explains the structure, the fault and the layer, and finely explains the structure by using a three-dimensional human-machine interaction explanation technology. On the basis, reservoir inversion is carried out by adopting a sparse pulse inversion method, reservoir interpretation is carried out by taking a deposition mode as guidance, and reservoir space distribution characteristics are realized.

FIG. 3 is a graph showing that the main frequency is increased from 27Hz to 35Hz by combining well-seismic, amplitude-preserving and frequency-increasing processing, and the resolution is obviously improved by comparison, so as to describe the structural characteristics; on the basis, reservoir inversion is carried out and sand thickness is described under the guidance of a deposition mode;

(3) FIG. 4 is limited by platform space, and the implementation principle of foot rolling is established, well positions are optimized, reasonable drilling sequence is formulated, designed well positions are adjusted in time, and reserves are arranged and controlled.

Controlling the scale of reserves integrally according to the' control well drilling first; the method comprises the following steps of tracking in real time, analyzing and adjusting in time, firstly, respectively implementing well positions from three different angles of a well pattern, seismic reflection and a reservoir in oil reservoir engineering, earthquake and geology, and combining the well positions to perform first round of well position optimization, designing well tracks, optimizing a well body structure, formulating a reasonable drilling sequence on the basis, and completing single well design; secondly, in the implementation process, the reservoir stratum re-recognition is carried out by performing drilling and drilling completion tracking, developing stratum comparison, structure and reservoir stratum research by combining logging and logging data; and finally, adjusting and deploying subsequent well positions according to the reservoir change condition.

Firstly, plan well position deployment is carried out from the angles of geology, earthquake and oil reservoir respectively, optimization is carried out, and a reasonable drilling sequence is formulated; secondly, in the implementation process, in the aspect of oil reservoirs, most wells are designed in a multi-target point mode, and more oil reservoirs are guaranteed to be drilled; plane displacements may not allow for large adjustments; one hole is drilled, prepared and designed instead of drilling the well in sequence; the requirement is high; the area of the artificial island is very small, only 90m is 150m, 61 new wells are drilled, the well opening distance is only 2-3m (figure 5), and therefore high-density drilling is carried out, overall collision prevention is carried out according to a drilling sequence proposed by geology, otherwise, some wells can not be implemented or the oil layer is sacrificed, and the benefit of the scheme is reduced. The maximum inclination angle of the new well after the block is drilled is 65.6 degrees, the maximum horizontal displacement is 2106 meters, and the horizontal displacement is more than 55 percent of 1000 meters.

(4) FIG. 6 shows that in the implementation of the southeast fault block of the southeast 5 of the Qingdong, two wells 5-1-x6 and 5-1-x16 which are drilled first encounter 3.1 m and 2.0m of oil layer and encounter oil-water interface respectively, which shows that the oil-bearing property of the north reservoir of the southeast block is deteriorated, the reserves of the southeast block are reduced by 169 ten thousand tons, the total well number is reduced by 9 wells, and the capacity scale is reduced by 3.4 ten thousand tons, because the working mode of the southeast land and artificial island is adopted, the early stage ground investment is already 5.4 billion, so the benefit of the whole scheme is greatly influenced, well-by-well analysis is carried out on 11 control wells which are drilled, and qd5-1-x1 wells are drilled with 30.9m of oil layer, the whole oil layer has a good trend towards the southeast, oil source comparative analysis is combined, the oil of the southeast 5 of the southeast block should come from two depressions of the southeast and the southeast, wherein the depression of the southeast is from the oil source, namely the important channel, the new oil reservoir block is designed by 3986, thus the new reservoir design of the new reservoir block of the southeast 5-3-5913. the new reservoir, the new reservoir structure is not needed to be evaluated by the design of the new⁴t, 5 new wells are deployed, and the productivity is increased by 2 × 10⁴t capacity. The synchronous implementation of the productivity construction well and the oil reservoir evaluation well is realized, the risk is reduced, the scheme quality is ensured, the geological reserves are used to the maximum extent, and the benefit development is realized.

(5) FIG. 7 is a three-dimensional view of the final Qingdong 5 completed well sites. The research area takes 9 months to finish drilling 61 new wells, and the drilling success rate is 100%.

Claims (1)

1. The rolling development method of the low-grade oil reservoir in the shoal and shoal sea is characterized by comprising the following steps:

step 1, developing fine oil reservoir description according to exploratory well data, and clearing reservoir development rules and reserve scales;

step 2, carrying out well-to-seismic combination, and depicting an interpretation structure and a fault by using a three-dimensional man-machine interaction interpretation technology and a coherent body seismic attribute processing technology;

step 3, formulating a reasonable drilling sequence, simulating a well track, and adjusting and deploying the next well position after the new well is designed and drilled;

step 4, combining newly completed well data, deploying an oil reservoir evaluation well for the unknown block, and synchronously implementing the oil reservoir evaluation well and the productivity building well; the unknown block reserves are implemented, and the overall capacity scale of the scheme is ensured;

in the step 1, according to the data of the drilled exploratory well, combining with core observation, according to the characteristics of deposition cycle in the longitudinal direction, combining with lithology and electrical characteristics, dividing a sand layer group into a target section of a research area, and dividing an oil-containing sand group into small layers and a single sand body on the basis; analyzing the development characteristics of a reservoir plane by applying analysis and logging data, determining the direction and the rule of a material source, analyzing oil reservoir control factors, implementing the scale of reserves, carrying out the preliminary conceptual design of a capacity scheme, carrying out oil testing and production trial on a completely drilled development and evaluation well, and clearly building a production position;

in step 2, three-dimensional seismic data are applied to perform seismic synthetic record calibration on the completed well, and the seismic synthetic record calibration and wavelet extraction are performed interactively; during calibration, firstly selecting Rake wavelets as synthetic seismic records, performing seismic calibration, then cutting a time window near a target layer, obtaining a constant-phase initial wavelet from seismic data by a multi-channel seismic record autocorrelation statistical method to obtain a synthetic record, then extracting the wavelet and then calibrating until the synthetic seismic record with a higher correlation coefficient is obtained; determining the time-depth relationship, performing fine structure interpretation by using a three-dimensional man-machine interaction interpretation technology, meanwhile, highlighting information related to the fault in the three-dimensional seismic body by combining a coherent body seismic attribute processing technology, and identifying and interpreting the fault to complete a target stratum structure diagram;

in step 3, firstly, plan well position deployment is carried out from the angles of geology, earthquake and oil reservoir respectively, well tracks are designed, well body structures are optimized, reasonable well drilling sequences are formulated on the basis, and single well design is completed; secondly, in the implementation process, the reservoir stratum re-recognition is carried out by performing drilling and drilling completion tracking, developing stratum comparison, structure and reservoir stratum research by combining logging and logging data; finally, adjusting and deploying subsequent well positions according to the reservoir change condition;

in the implementation process, a rolling implementation principle is adopted, the concept of controlling the well to be drilled firstly, controlling the reserve size integrally, tracking in real time, analyzing and adjusting in time, making a reasonable drilling sequence, simulating well tracks, analyzing the change of the structure and the reservoir in the plane and the longitudinal direction by combining well completion data at the first time after a new well is designed and drilled, adjusting and deploying the next well position in time, and realizing a well scheme;

in step 4, with continuous drilling of new wells, reservoir and oil reservoir characteristics are researched, oil reservoir evaluation wells are deployed on the unknown blocks, and are synchronously implemented with the oil reservoir evaluation wells, so that the reserves of the unknown blocks are implemented; the reduction of the number of designed wells caused by the deterioration of a reservoir layer in the drilling process is avoided, and the whole capacity scale of the scheme is ensured.

Images