Fault Block Oilfield Research Articles

Fine Characterization of Nonmain Oil Layer Distributions in Complex Fault Block Oilfield and Its Development Model

Fine Characterization of Nonmain Oil Layer Distributions in Complex Fault Block Oilfield and Its Development Model

Effective Water Injection Development Test for Rolling Outward Expansion of Low-grade Reservoir

The development of ultra-low permeability reservoirs in the oilfield mainly involves a large proportion of ultra-low permeability and it is difficult to recover reserves because of scattered distribution, low reserve abundance, poor reservoir physical property, and great development difficulty as well as low production intensity, rapid production decline, and low stable production of oil wells. In order to speed up the development of undeveloped reserves and explore the effective technical approach to solve problems in low permeability and difficulty in recovering reservoirs, we carried out the effective water injection development test in the B1 test area. In this paper, in-depth research has been carried out in reservoir geological understanding, development well pattern design optimization, and advanced water injection technology research. Finally, a set of effective production technologies for low abundance reserves in complex geological conditions are formed, effective production in B1 Block that was hard to recover reserves is realized, the drilling success rate is improved greatly, and well pattern design optimization is achieved, advanced water injection efficient development technologies for low abundance reserves blocks are also developed. The demand for rolling production can be gradually extended to other oilfields, which has certain reference significance for the development practice of peripheral oilfields and similar small complex fault block oilfields.

Interpretation of Sand Body Architecture in Complex Fault Block Area of Craton Basin: Case Study of TIII in Sangtamu Area, Tarim Basin

The complex fault block oilfields in the craton basin contain vast reserves of oil and gas resources. During the development of an oilfield, the flow of oil, gas, and water, is controlled by faults and configuration boundaries. The distribution of remaining oil and gas depends on the interpretation of the reservoir’s architecture. However, recognizing the faults and the architecture boundary remains a challenge, hindering the efficient development of these resources. This study proposes a new idea for interpreting the configuration of thick sand bodies. This study was conducted in order to interpret the fine architecture of thick sand bodies in the Sangtamu area, using core samples, well logging, and production data, guided by sedimentation patterns from ancient to modern times. Results indicate that the Sangtamu area is a braided river delta front sedimentary system, dominated by the backbone underwater distributary channel and branch-type underwater distributary channels. The backbone channel is larger in scale, with a relatively large rock grain size and a box-shaped logging curve, whereas the smaller-scale branch channels have a bell-shaped logging curve resulting from the gradual weakening of water energy. Sandstone bodies from different types of underwater distributary channels are spatially overlapped, forming thick plate-like sandstones. The architecture interface between channels can be used as the fluid seepage boundary and can help prevent bottom water intrusion to a certain extent. The remaining oil is primarily concentrated in the architecture boundary area, which presents the next potential tapping area.

Study on Fault Lateral Sealing Based on SGR Method

Bozhong A Oilfield is located in the northeast of Huanghekou Sag in the Bohai Bay Basin, and is a complex fault block oilfield. The main oil bearing horizon is the lower Minghuazhen Member, belonging to shallow water delta sedimentation. For the rolling exploration and evaluation of adjacent fault blocks, this paper uses the mudstone smear method to analyze and accurately characterize the lithological contact relationship between the two walls of the fault. Based on the establishment of different reservoir docking modes on the two walls of the fault, the sealing parameters are calculated to evaluate the sealing ability of the fault, thereby evaluating its reservoir formation characteristics, and predicting the height of the oil column. The above methods provide geological basis for further rolling expansion and potential tapping in the study area and surrounding areas, and have guiding significance for exploration and rolling potential tapping in similar blocks in the Bohai Sea.

Study on reservoir description technology of complex fault block oilfield——Taking the South 1st member of D sag as an example

The D sag has developed faults, serious erosion and fault loss, developed glutamate, strong heterogeneity, and large formation dip, which makes stratigraphic comparison difficult and unclear understanding of oil reservoir and oil-water relationship during the development process. For this reason, this study was carried out. On the basis of the existing seismic interpretation results, carry out the fine structural interpretation of the main sub-layers in the study area; carry out the study of sedimentary characteristics, divide the sedimentary facies, and clarify the sedimentary characteristics of the main sand bodies; use the core analysis data to establish the interpretation of physical parameters in the study area model, and establish a fine three-dimensional geological model, through the study of oil-water distribution law, carry out potential research, and select favorable well-distributed blocks.

Study on Water Reduction, Oil Stabilization and Efficiency Enhancement in Complex Fault-Block Oilfield at the Late Stage of High Water Cut Development

Study on Water Reduction, Oil Stabilization and Efficiency Enhancement in Complex Fault-Block Oilfield at the Late Stage of High Water Cut Development

Optimization of large-scale fracturing technology and improvement of development effect of hard-to-recover reservoirs

At present, the development of unconventional and low-permeability oil and gas reservoirs has become a hot spot of energy development at home and abroad. The typical feature of this kind of oil and gas reservoirs is that the reservoir permeability is very low, and certain transformation measures need to be taken before they can be put into operation. The reservoir volume transformation technology is one of the important technologies for the effective development of unconventional oil and gas reservoirs. In recent years, in order to improve the development effect of ultra-low permeability reservoir, Hailar complex fault block oilfield has carried out field application tests of volume transformation technology in different types of reservoirs year by year. By increasing the amount of fracturing fluid and fracturing sand, increasing the fracturing sweep volume and improving the reservoir seepage conditions, the effective production of the reservoir is realized. However, from the perspective of fracturing effects of different reservoirs, there will be great differences in fracturing effects under the same fracturing method. It shows that the effect of large-scale fracturing development of oil and gas reservoir is related not only to the fracturing mode, but also to the geological characteristics of the fracturing horizon. The in-depth study of the factors affecting the fracturing effect has important guiding significance for the development of low-permeability reservoirs.

Research on large-scale clean water mesh fracturing technology

hailaer oilfield belongs to low permeability fault-block oilfield, some blocks effectively injection Wells after fracturing is still hard, lead to low formation pressure, the late refracturing effect is poor, single and average increased under 400 t oil and to explore effective fracturing technology in the low permeability elastic exploration area, hailaer oilfield since 2011, in fissured budate reservoir, according to the characteristics of the reservoir Large-scale clear water fracture network fracturing tests have been carried out, and better stimulation effect has been achieved. The tests have guiding significance for the effective development of low efficiency and difficult to recover reservoirs in Hailaer oilfield.

Application of Oily Cuttings Extraction Technology in the East China Sea

The oil-based drilling fluid has the characteristics of strong inhibition, good lubricity and low damage degree to oil and gas formations, which can effectively solve the problems of high reservoir protection requirements, poor borehole stability, and difficult drilling in complex fault block oil and gas fields in the East China Sea. However, this also inevitably produces a large amount of oil-filled drill cuttings, which shows a higher risk of environmental pollution or has to bear a high cost of pollution prevention. This paper introduces the working principle, equipment composition and technological process of oil-bearing drilling cuttings extraction treatment technology, and then analyzes and summarizes the application of this technology in the East China Sea by taking well A as an example. The results of the field application show that this technology can remove the oil components from the oil-bearing drilling with efficient solvent, meet the offshore requirements of the environment protection, and reduce the risk of environmental contamination and the cost of anti-pollution greatly.

Prediction method of formation pressure for the adjustment well in the reservoir with fault

Adjustment wells need to be deployed in the middle and late stages of oilfield development to improve development efficiency. However, the multiple pressure systems would be happened in the fault block oilfields due to the geological faults are developed and multi-layer joint water injection. The well kick and leakage would happen during drilling and completion operations of adjustment well because of the large dynamic pressure changes such as high-pressure or low-pressure. A pressure prediction method established base on seepage theory and fluid mechanics theory in order to ensure the safety operations during the adjustment well drilling and completion. This method could predict the maximum formation pressure of adjustment wells in complex fault block reservoirs by considering the influence of faults and surrounding injection-production wells. The error between prediction results and numerical simulation results is less than 10% based on Bohai fault block oilfield. The scheme of shut-in of surrounding water injection wells during drilling and completion of adjustment wells in fault block oilfield is given. This method has significance guidance for the design of shut in adjustment well drilling and completion.

Analysis on the Development Status and Countermeasures of Fault Block Reservoir in Middle and Late Stage

China is a country with rich oil reserves. With the development of the reservoir, the proportion of fault block reservoir (hereinafter referred to as FBR) discovery increases gradually. At present, FBR has occupied a considerable proportion of China’s oil reserves. Zhongyuan Oilfield is mainly composed of complex FBR. FBR has unique characteristics, such as small fault block and complex geological structure, which will greatly increase the difficulty of development in the middle and late development. Therefore, we must comprehensively adjust and tap the potential of FBR, which will achieve long-term stable production in the middle and late stage of fault block oilfield. Therefore, based on the characteristics and classification of FBR, this paper analyzes the development status in the middle and late stage. Then, according to the characteristics of fault block oilfield in the middle and late stage, this paper puts forward some comprehensive adjustment technical measures, which will better adapt to the reasonable development mode of FBR in the middle and late stage.

黄河口凹陷复杂断块油气田水平井着陆技术

黄河口凹陷复杂断块油气田水平井着陆技术

老井复查技术在小断块油田的应用研究

老井复查技术在小断块油田的应用研究

Application of Pressure Data Analysis in Tapping the Potential of Complex Fault Block Oilfield

The B oilfield in Bohai Bay Basin is the fluvial facies sedimentary, reservoir thickness varies rapidly in lateral direction, and what is worse the fracture system is very developed, petroleum reserves are small within a single block. Due to the poor quality of seismic data, the sealing of fault and reservoir connectivity is unclear which directly affect the understanding of reserves and adjusting injection-production well pattern. This paper introduces the working principle of StethoScope, and use formation pressure testing by StethoScope analyzing the fluid system and reserve scale, which can indirectly judge the sealing of fault and reservoir connectivity. This method provides a reliable basis for well pattern deployment.

Geometry, kinematics and dynamic characteristics of a compound transfer zone: the Dongying anticline, Bohai Bay Basin, eastern China

AbstractThe Dongying anticline is an E-W striking complex fault-bounded block unit which located in the central Dongying Depression, Bohai Bay Basin. The anticline covers an area of approximately 12 km2. The overlying succession, which is mainly composed of Tertiary strata, is cut by normal faults with opposing dips. In terms of the general structure, the study area is located in a compound transfer zone with major bounding faults to the west (Ying 1 fault) and east (Ying -8 and -31 faults). Using three-dimensional seismic data, wireline log and checkshot data, the geometries and kinematics of faults in the transfer zone were studied, and fault displacements were calculated. The results show that when activity on the Ying 1 fault diminished, displacement was transferred to the Ying -8, Ying -31 and secondary faults so that total displacement increased. Dynamic analysis shows that the stress fields in the transfer zone were complex: the northern portion was a left-lateral extensional shear zone, and the southern portion was a right-lateral extensional shear zone. A model of potential hydrocarbon traps in the Dongying transfer zone was constructed based on the above data combined with the observed reservoir rock distribution and the sealing characteristics of the faults. The hydrocarbons were mainly expulsed from Minfeng Sag during deposition periods of Neogene Guantao and Minghuazhen Formations, and migrated along major faults from source kitchens to reservoirs. The secondary faults acted as barriers, resulting in the formation of fault-bound compartments. The high points of the anticline and well-sealed traps near secondary faults are potential targets. This paper provides a reservoir formation model of the low-order transfer zone and can be applied to the hydrocarbon exploration in transfer zones, especially the complex fault block oilfields in eastern China.

Fault Sealing Property Analyzing by Water Injection in Oilfields

The quantity and availability of water injection are affected by geological environments in complex small fault-block oilfields, especially nearby faults. It is a general method to qualitatively determine fault sealing ability by water injection availability. The availability analysis of several injection wells can judge sealing ability of five faults of block M28-1 in JD oilfield. The water injection data show that fault F1, F4, F5 are main areas of pressure releasing for unsealing. Fault F2 and F3 are distributed on each side of the water injection well, which have a little influence on loss of water injection for sealing.

Sequence stratigraphic analysis and integrated 3D geological modeling of M1 block, Wenmingzhai oilfield, Dongpu depression, China

AbstractThe M1 block is a typically complex fault-block oilfield, whose recovery has reached 30.5% through the twenty years waterflooding development. Remaining oil scatters very widely and the production between layers is in a high degree. However, many problems have been exposed at the same time which hinder improvement of the recovery rate and sustainable development of the reservoir. Hence, it is important to carry out basic geological research and form a comprehensive understanding of reservoir properties. However, few such studies have been conducted in China. In this study, work related to basic geological research was conducted based on high-resolution sequence stratigraphy, seismic interpretation technology and 3D visual geological modeling, and significant results were achieved. Three sequence orders and three types of interfacies in the stratigraphic architecture of M1 block were identified through seismic sections, logging curve characteristics and entropy spectrum analysis. Thirty-two short-term sequence cycles (fifth order), eight mid-term sequence cycles (fourth order) and two long-term sequence cycles (third order) were identified, followed by the establishment of a high-resolution isochronous stratigraphic correlation framework. Finally, a regional 3D geological model was established on the basis of these preliminary studies. The integrated 3D geological model is a valuable tool for reflecting geological bodies accurately, and it can accurately represent and describe reservoir heterogeneity.

Gray Fuzzy Cluster Method and its Application in Development Scheme of Fault Block Reservoirs

Fault-block oil and Gas Field is one of special complicated reservoirs. For its development, No matter at home or aboard, the instances are not too many, and most of them are terrestrial oil reservoir. For ocean fault-block oil reservoirs, there are no instances that can be consulted. This paper aims at some ocean fault block oil reservoir .Gray relation model and fuzzy cluster analysis are combined to set gray fuzzy cluster analysis .Through a case analysis ,gray fuzzy cluster method is used to clustering of reservoirs. with the experiences that has been obtained, so that the foundation are provided for the development of some ocean fault block oil reservoir.

Development Characteristics and Development Adjustment Countermeasures of Wangji Oilfield

Wangji oilfield is a complicated fault-block oilfield, with many oil-bearing systems and severe heterogeneity. More and more problems and conflicts are exposed during the production and it is hard to produce the remaining oil, when entering into the medium-late water cut stage. In this paper, current development characteristics and main existing problems of Wangji oilfield are analyzed, including low development degrees of reserve, low recovery percent, low oil recovery rate, low perfecting degree of well pattern and so on. The combined research means of reservoir performance analysis and numerical simulation are used to analyze the distribution characteristics and rich region of remaining oil, then, the technology policies of vector well pattern[1] adjustment which is suitable for later development was put forward. Based on these, the injection-production system was adjusted, the injection - production corresponding relation was improved and the economic benefit was increased, which possesses reference meaning in the development of the similar oilfield in future.