Study on water flooding of fractured reservoirs with complex structure well pattern

2013 ◽  
pp. 253-258
Author(s):  
J Liu ◽  
Y Liu ◽  
Z Guo ◽  
E Li ◽  
Z Zheng
Keyword(s):  
Fractured Reservoirs ◽  
Complex Structure ◽  
Water Flooding ◽  
Well Pattern

scholarly journals Reservoir characteristics and effective development technology in typical low-permeability to ultralow-permeability reservoirs of China National Petroleum Corporation

2021 ◽  
pp. 014459872110052
Author(s):  
Xizhe Li ◽  
Zhengming Yang ◽  
Shujun Li ◽  
Wei Huang ◽  
Jianfei Zhan ◽  
...  
Keyword(s):  
Horizontal Well ◽  
Water Flooding ◽  
Low Permeability ◽  
Reservoir Characteristics ◽  
Well Pattern ◽  
China National Petroleum Corporation ◽  
Volume Fracturing ◽  
Effective Development ◽  
Oil Gas ◽  
Ultralow Permeability

Low-permeability to ultralow-permeability reservoirs of the China National Petroleum Corporation are crucial to increase the reserve volumes and the production of crude oil in the present and future times. This study aimed to address the two major technical bottlenecks faced by the low-permeability to ultralow-permeability reservoirs by a comprehensive use of technologies and methods such as rate-controlled mercury injection, nuclear magnetic resonance, conventional logging, physical simulation, numerical simulation, and field practices. The reservoir characteristics of low-permeability to ultralow-permeability reservoirs were first analyzed. The water flooding development adjustment mode in the middle and high water-cut stages for the low-permeability to ultralow-permeability reservoirs, where water is injected along the fracture zone and lateral displacement were established. The formation mechanism and distribution principles of dynamic fractures, residual oil description, and expanding sweep volume were studied. The development mode for Type II ultralow-permeability reservoirs with a combination of horizontal well and volume fracturing was determined; this led to a significant improvement in the initial stages of single-well production. The volume fracturing core theory and optimization design, horizontal well trajectory optimization adjustment, horizontal well injection-production well pattern optimization, and horizontal well staged fracturing suitable for reservoirs with different characteristics were developed. This understanding of the reservoir characteristics and the breakthrough of key technologies for effective development will substantially support the oil-gas valent weight of the Changqing Oilfield to exceed 50 million tons per year, the stable production of the Daqing Oilfield with 40 million tons per year (oil-gas valent weight), and the realization of 20 million tons per year (oil-gas valent weight) in the Xinjiang Oilfield.

Forecasting the Water Flooding for the Production Wells of a Gas Condensate Field with a Fractured Reservoir Type

2021 ◽  
Author(s):  
Pavel Dmitrievich Gladkov ◽  
Anastasiia Vladimirovna Zheltikova
Keyword(s):  
Produced Water ◽  
Fractured Reservoirs ◽  
Gas Condensate ◽  
Water Flooding ◽  
Fractured Reservoir ◽  
Well Performance ◽  
Integrated Monitoring ◽  
Field Development ◽  
Water Gas ◽  
Gas Ratio

Abstract As is known, fractured reservoirs compared to conventional reservoirs have such features as complex pore volume structure, high heterogeneity of the porosity and permeability properties etc. Apart from this, the productivity of a specific well is defined above all by the number of natural fractures penetrated by the wellbore and their properties. Development of fractured reservoirs is associated with a number of issues, one of which is related to uneven and accelerated water flooding due to water breakthrough through fractures to the wellbores, for this reason it becomes difficult to forecast the well performance. Under conditions of lack of information on the reservoir structure and aquifer activity, the 3D digital models of the field generated using the hydrodynamic simulators may feature insufficient predictive capability. However, forecasting of breakthroughs is important in terms of generating reliable HC and water production profiles and decision-making on reservoir management and field facilities for produced water treatment. Identification of possible sources of water flooding and planning of individual parameters of production well operation for the purpose of extending the water-free operation period play significant role in the development of these reservoirs. The purpose of this study is to describe the results of the hydrochemical monitoring to forecast the water flooding of the wells that penetrated a fractured reservoir on the example of a gas condensate field in Bolivia. The study contains data on the field development status and associated difficulties and uncertainties. The initial data were results of monthly analyses of the produced water and the water-gas ratio dynamics that were analyzed and compared to the data on the analogue fields. The data analysis demonstrated that first signs of water flooding for the wells of the field under study may be diagnosed through the monitoring of the produced water mineralization - the water-gas ratio (WGR) increase is preceded by the mineralization increase that may be observed approximately a month earlier. However, the data on the analogue fields shows that this period may be longer – from few months to two years. Thus, the hydrochemical method within integrated monitoring of development of a field with a fractured reservoir could be one of the efficient methods to timely adjust the well operation parameters and may extend the water-free period of its operation.

The Research of Flood Pattern Completeness in the Thin and Poor Oil Layers of South West II Area

2012 ◽  
Vol 594-597 ◽  
pp. 2541-2544
Author(s):  
Xiao Hui Wu ◽  
Kao Ping Song ◽  
Chi Dong ◽  
Ji Cheng Zhang ◽  
Jing Fu Deng
Keyword(s):  
Oil Recovery ◽  
Water Flooding ◽  
South West ◽  
Oil Distribution ◽  
Well Pattern ◽  
Remaining Oil ◽  
Tertiary Oil Recovery ◽  
Well Pattern Optimization ◽  
Numerical Simulation Technique

As line well pattern is the main development technique in the thin and poor oil layers of Daqing Oilfield South West Ⅱ PⅠ group, the layers have been idle and the degree of reserve recovery is far less than the region level. In response to these problems, we analyzed the balanced flood performance of various layers and the remaining oil distribution through numerical simulation technique. It shows that, the main remaining oil type of intended layers is caused by voidage-injection imperfection. Considering the needs of the follow-up infill well pattern and tertiary oil recovery, we decided to keep the well network independent and integrated without disturbing the pattern configuration and main mining object of various sets of well pattern. Finally we confirmed to perforate-adding the first infill wells of intended layers to consummate the water flooding regime. Through analyzing the production target of different well pattern optimization programs relatively, it shows that the best program has regular well pattern and large drilled thickness.

A Simplified and Efficient Method for Water Flooding Production Index Calculations in Low Permeable Fractured Reservoir

2019 ◽  
Vol 141 (11) ◽  
Author(s):  
Shun Liu ◽  
Liming Zhang ◽  
Kai Zhang ◽  
Jianren Zhou ◽  
Heng He ◽  
...  
Keyword(s):  
Fractured Reservoirs ◽  
Water Injection ◽  
Cross Flow ◽  
Production Performance ◽  
Water Flooding ◽  
Simplified Model ◽  
Single Fracture ◽  
Fractured Reservoir ◽  
Production Index ◽  
Future Production

Presently, predicting the production performance of fractured reservoirs is often challenging because of the following two factors: one factor such as complicatedly connected and random distribution nature of the fractures and the other factor includes the limitations of the understanding of reservoir geology, deficient fracture-related research, and defective simulators. To overcome the difficulties of simulating and predicting fractured reservoir under complex circumstances of cross flow, a simplified model, which assumes cross flow only exists in the oil phase segment, is constructed. In the model, the pressure distribution of a single fracture can be described by solving an analytical mathematical model. In addition, due to research and field experience which indicate that cross flow also exists in the mixed-phase segment after water injection, the simplified model is modified to consider cross flow in the whole phase. The model constructed here is applicable for fractured reservoirs especially for a low-permeability fracture reservoir, and it moderately predicts future production index. By using iterative methods, the solution to the model can be feasibly obtained and related production performance index formulas can be derived explicitly. A case study was performed to test the model, and the results prove that it is good.

scholarly journals Asynchronous Injection-Production Process: A Method to Improve Water Flooding Recovery in Complex Fault Block Reservoirs

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Shibao Yuan ◽  
Rui Wang ◽  
Haiyan Jiang ◽  
Qing Xie ◽  
Shengnan Chen ◽  
...  
Keyword(s):  
Production Process ◽  
Oil Recovery ◽  
Water Injection ◽  
Central Area ◽  
Water Flooding ◽  
Production Stage ◽  
Fault Block ◽  
Complex Fault ◽  
Well Pattern ◽  
Remaining Oil

The complex fault block reservoir has the characteristics of small area and many layers in vertical. Due to the influence of formation heterogeneity and well pattern, the situation that “water fingering is serious with water injection, on the contrary, driving energy is low” frequently occurs in water flooding, which makes it difficult to enhance oil recovery. Asynchronous injection-production (AIP) process divides the conventional continuous injection-production process into two independent processes: injection stage and production stage. In order to study oil recovery in the fault block reservoir by AIP technology, a triangle closed block reservoir is divided into 7 subareas. The result of numerical simulation indicates that all subareas have the characteristic of fluid diverting and remaining oil in the central area is also affected by injected water at injection stage of AIP technology. Remaining oil in the central area is driven to the included angle and border area by injected water and then produced at the production stage. Finally, the oil recovery in the central area rises by 5.2% and in the noncentral area is also increased in different levels. The AIP process can realize the alternative change of reservoir pressure, change the distribution of flow field, and enlarge the swept area by injected water. To sum it up, the AIP process is an effective method to improve the oil recovery in complex fault-block reservoir by water flooding.

Use of Diverter Compositions for Enhancing the Effectiveness of Oil Recovery from Productive Deposits

2018 ◽  
Vol 785 ◽  
pp. 159-170
Author(s):  
Vadim Aleksandrov ◽  
Kirill Galinskij ◽  
Andrey Ponomarev ◽  
Vadim Golozubenko ◽  
Yuriy Sivkov
Keyword(s):  
Oil Recovery ◽  
Complex Structure ◽  
Water Injection ◽  
Geological Structure ◽  
Oil Field ◽  
Field Analysis ◽  
Water Flooding ◽  
Simple Method ◽  
Oil Companies ◽  
Porosity And Permeability

One of the most important aspects in the activities of oil companies in the Western Siberia is to improve the effectiveness of water-flooding as the main method of impact on the formation. This is due to the fact that at the present time reservoirs of a complex structure with difficult to recover reserves prevail among newly introduced development objects, the extraction of which is extremely difficult using a simple method of water injection volumes regulation. First of all, this refers to reservoirs of Jurassic deposits, which are characterized by the most complex geological structure and porosity and permeability properties. A promising direction in improving the water-flooding system at such objects is the use of physical and chemical technologies to enhance the oil recovery of formations, and primarily, referring to the diverter technology. The research objective is to evaluate the effectiveness of using “hard” type diverter compositions to enhance oil recovery of formations. With the help of detailed oil-field analysis and field-geophysical studies, the nature of the development of oil reserves for Jurassic development sites has been assessed.

scholarly journals Experiments on the influences of well pattern on water flooding characteristics of dissolution vug-cave reservoir

2018 ◽  
Vol 45 (6) ◽  
pp. 1103-1111 ◽  
Author(s):  
Jing WANG ◽  
Huiqing LIU ◽  
Jing ZHANG ◽  
Wei ZHAO ◽  
Yitao HUANG ◽  
...  
Keyword(s):  
Water Flooding ◽  
Well Pattern

scholarly journals Investigation of acid pre-flushing and pH-sensitive microgel injection in fractured carbonate rocks for conformance control purposes

2020 ◽  
Vol 75 ◽  
pp. 52
Author(s):  
Alireza Teimouri ◽  
Saeid Sadeghnejad ◽  
Amir Hossein Saeedi Dehaghani
Keyword(s):  
Flow Rate ◽  
Control Method ◽  
Fractured Reservoirs ◽  
Water Injection ◽  
Ph Sensitive ◽  
Water Flooding ◽  
Fracture Aperture ◽  
Visual Cell ◽  
Conformance Control ◽  
Fractured Carbonate

Waterflooding in fractured reservoirs is a challenging task due to the presence of high conductive flow pathways such as fractures. Much of the injected water passes through fractures without sweeping the oil in the low permeable area, which results in an early breakthrough. Implementing deep conformance control techniques can be a remedy for this early water breakthrough. pH-sensitive microgel injection is a conformance control method in which the dependency of microgel viscosity to pH guarantees easy injection of these microgels into formations at low pH environments. Because of the geochemical reactions among rock minerals, microgels, and a pre-flushing acid, the microgel pH increases; therefore, these microgels swell and block high conductive fractures. In this study, a designed visual cell containing rock samples is implemented to observe rock–microgel interactions during a pH-sensitive microgel flooding into a fractured carbonate medium. First, the dependency of fracture aperture changes to the acid pre-flush flow rate is examined. Then, we investigate the effect of pH-sensitive microgel concentration on its resistance to block fractures during post-water flooding by studying the gel failure mechanisms (e.g., adhesive separation, cohesive failure). Finally, the effect of an initial aperture of fracture is examined on microgel washout when water injection is resumed. The results showed that both decreasing the acid flow rate and lowering the initial aperture could increase the rate of aperture changes. Moreover, the microgel solution with a concentration of 1 wt% showed the highest resistance (98.2 psi/ft) against post-water injection. Additionally, this microgel concentration had the highest permeability reduction factor. Meanwhile, the smaller initial aperture of fracture contributed to a higher microgel resistance.

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