The Performance Evaluation of Old Well after SRV in Ordos Basin Tight Oil Reservoir

2014 ◽  
Author(s):  
H.. Wang ◽  
X.. Liao ◽  
H.. Ye ◽  
X.. Zhao ◽  
C.. Liao ◽  
...  
Keyword(s):  
Evaluation Method ◽  
Ordos Basin ◽  
Fracture Network ◽  
Water Flooding ◽  
Tight Oil ◽  
Oil Reservoir ◽  
Well Test ◽  
Stimulated Reservoir Volume ◽  
Tight Oil Reservoir ◽  
Volume Fracturing

Abstract The technology of Stimulated reservoir volume (SRV) has been the key technology for unconventional reservoir development, it can create fracture network in formation and increase the contact area between fracture surface and matrix, thus realizing the three-dimensional stimulation and enhancing single well productivity and ultimate recovery. In China, the Ordos Basin contains large areas of tight oil reservoir with the porosity of 2~12 % and permeability of 0.01~1 mD. The most used development mode is conventional fracturing and water flooding, which is different from the natural depletion mode in oversea, but the development effect is still unfavorable. The idea of SRV is proposed in nearly two years in Changqing Oilfield. SRV measures are implemented in some old wells in tight oil formation. It is a significant problem that should be solved urgently about how to evaluate the volume fracturing effect. Based on the real cases of old wells with SRV measures, the microseismic monitoring is used to analyze the scale of formation stimulation and the complexity of fracture network after volume fracturing; the numerical well test and production data analysis (PDA) are selected to explain the well test data, to analyze the dynamic data, and to compare the changes of formation parameters, fluid parameters and plane streamlines before and after volume fracturing; then the interpretation results of well test with the dynamic of oil and water wells are combined to evaluate the stimulation results of old wells after SRV. This paper has presented a set of screening criteria and an evaluation method of fracturing effect for old well with SRV in tight oil reservoir. It will be helpful to the selection of candidate well and volume fracturing operation in Ordos Basin tight oil reservoir. It should be noted that the evaluation method mentioned in the paper can be expanded to volume stimulation effect evaluation in other unconventional reservoirs, such as tight gas, shale gas and so on.

Development and Application of Cyclic Stress Fracturing for Tight Oil Reservoir in Ordos Basin

2019 ◽  
Author(s):  
Xiaohu Bai ◽  
Kuangsheng Zhang ◽  
Meirong Tang ◽  
Chengwang Wang ◽  
Guanggao Wang ◽  
...  
Keyword(s):  
Ordos Basin ◽  
Cyclic Stress ◽  
Tight Oil ◽  
Oil Reservoir ◽  
Tight Oil Reservoir

A History Matching Framework to Characterize Fracture Network and Reservoir Properties in Tight Oil

2019 ◽  
Vol 142 (4) ◽  
Author(s):  
Xu Shiqian ◽  
Li Yuyao ◽  
Zhao Yu ◽  
Wang Sen ◽  
Feng Qihong
Keyword(s):  
History Matching ◽  
Fracture Network ◽  
Future Application ◽  
Tight Oil ◽  
Oil Reservoir ◽  
Fracture Permeability ◽  
Reservoir Properties ◽  
Matrix Permeability ◽  
Tight Oil Reservoir ◽  
Better Than

Abstract Accurately characterizing hydraulic fracture network and tight oil reservoir properties can lay the foundation for the production forecast and development design. In this work, we proposed a history matching framework for tight oil. We first use the Hough transform method to characterize complex fracture network from microseismic data. Then, we put the fracture network into an embedded discrete fracture model (EDFM) to build a tight oil reservoir simulation model. After that, we further couple whale optimization algorithm (WOA) and EDFM to match the field production data. In this way, we can accurately estimate reservoir properties, including matrix permeability and porosity, as well as fracture permeability. We apply the framework to two-field applications in China. One is fractured vertical well in the Songliao Basin of Daqing oilfield. The other one is multi-stage fractured horizontal well in the Jimsar Sag of the Xinjiang oilfield. Results show that if we do not consider tight oil characteristics, the estimated fracture permeability, matrix permeability, and matrix porosity will underestimate 73%, 20%, and 47%, respectively. Because we apply WOA to history matching for the first time, we compare the performance of WOA with ensemble–smoother with multiple data–assimilation (ES-MDA). When we fit six parameters, ES-MDA performs better than WOA. However, when we fit three parameters, WOA performs better than ES-MDA. In addition, for engineering problem, WOA performs well on both convergence speed and stability. Therefore, WOA is recommended in the future application of history matching.

scholarly journals A New Methodology for the Multilayer Tight Oil Reservoir Water Injection Efficiency Evaluation and Real-Time Optimization

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Lin Cao ◽  
Jianlong Xiu ◽  
Hongjie Cheng ◽  
Hui Wang ◽  
Shujian Xie ◽  
...  
Keyword(s):  
Water Injection ◽  
Sedimentary Facies ◽  
Production Performance ◽  
Water Flooding ◽  
Tight Oil ◽  
Oil Reservoir ◽  
Reservoir Water ◽  
Injection Efficiency ◽  
Tight Oil Reservoir ◽  
Channel Bar

It is important to determine the reasonable injection and production rates in the development of multilayer tight oil reservoir with water flooding treatment. Based on the INSIM (interconnection-based numeric simulation model), a connected network model, a new method is designed to evaluate the water injection efficiency of different layers in water flooding reservoirs and to optimize the injection-production system to produce more oil. Based on the types of sedimentary facies and corresponding injection-production data, the interwell connections are divided into four major categories (middle channel, channel edge, middle channel bar, and channel bar edge) and twelve subclasses. This classification standard of interwell connections could help to significantly improve the accuracy of judging the dominant flow path without constructing a complicated geological model. The interaction of interwells such as injection-production correlation and water injection efficiency could be revealed by simulating the production performance and computing the layer dividing coefficient and well dividing coefficient. A numerical example is used to validate this method by comparing results from FrontSim and this method, and the computational efficiency of this method is several dozen times faster than that of the traditional numerical simulation. This method is applied to quickly optimize the production schedule of a tight oil reservoir with the water flooding treatment, that is, the water injection rate of multilayer reservoirs could be optimized subtly by the injection efficiency of different layers, and the target of producing more oil with lower water cut could be achieved.

CO2 Sequestration-EOR in a Tight Oil Reservoir: Estimation of Dynamic CO2 Storage Capacity Using a Two-Stage Well Test

2019 ◽  
Author(s):  
Vahab Honari ◽  
Jim Underschultz ◽  
Andrew Garnett ◽  
Xingjin Wang ◽  
Xiangzeng Wang ◽  
...  
Keyword(s):  
Co2 Sequestration ◽  
Storage Capacity ◽  
Co2 Storage ◽  
Tight Oil ◽  
Oil Reservoir ◽  
Well Test ◽  
Two Stage ◽  
Tight Oil Reservoir

The Study of CO2 Flooding of Horizontal Well with SRV in Tight Oil Reservoir

2014 ◽  
Author(s):  
H.. Wang ◽  
X.. Liao ◽  
X.. Zhao ◽  
H.. Ye ◽  
X.. Dou ◽  
...  
Keyword(s):  
Horizontal Well ◽  
Ordos Basin ◽  
Gas Injection ◽  
Tight Oil ◽  
Oil Reservoir ◽  
Co2 Flooding ◽  
Vertical Wells ◽  
Injection Volume ◽  
Fractured Horizontal Well ◽  
Tight Oil Reservoir

Abstract As one kind of unconventional reservoirs, tight oil reservoir has become one of the main forces of oil reserves and production growth. The characteristics of tight oil reservoir are low porosity and ultra-low permeability, thus stimulated reservoir volume (SRV) should be conducted whether applying the mode of vertical wells or horizontal wells production. Tight oil reservoir is mostly developed by natural depletion or water flooding recently, but the problems are existed, including low recovery factor with natural depletion and the difficulty of water injection. To further improve the development effect of tight oil reservoir, CO2 flooding is proposed. Based on chang-8 tight oil reservoir in Ordos Basin, an oil sample of typical block is selected. The PVT experiments are conducted. The compositional numerical model of five-spot pattern is established with a horizontal well in the middle and 4 vertical wells on the edge. Based on the model, several CO2 flooding scenarios of horizontal well with different completion measures are studied. Furthermore, parameters such as the formation pressure, production rate, shut-in gas-oil ratio and total gas injection volume are optimized. The results of this study show that the recovery factor of horizontal well with SRV is higher than those of horizontal well and conventional fractured horizontal well. The minimum miscible pressure (MMP) and the total gas injection volume are two key factors of CO2 flooding effect. CO2 flooding of volume fractured horizontal well in tight oil reservoir can not only improve oil recovery, but also realize CO2 geological sequestration. It plays dual benefits of economy and environment. The study gives new ideas of CO2 flooding with volume fractured horizontal well for the Ordos Basin tight oil reservoir. It can be helpful for rapid and effective development of tight oil reservoirs in Ordos Basin.

Spatiotemporal variations in seismic attenuation during hydraulic fracturing: A case study in a tight oil reservoir in the Ordos Basin, China

Geophysics ◽  
2021 ◽  
pp. 1-56
Author(s):  
Han Li ◽  
Xu Chang ◽  
Xiao-Bi Xie ◽  
Yibo Wang
Keyword(s):  
Hydraulic Fracturing ◽  
Ordos Basin ◽  
Seismic Attenuation ◽  
Tight Oil ◽  
Oil Reservoir ◽  
Spatiotemporal Variations ◽  
Waveform Data ◽  
Log Data ◽  
The Ordos Basin ◽  
Tight Oil Reservoir

During hydraulic fracturing (HF) stimulation for unconventional reservoir development, seismic attenuation has a significant influence on high-frequency microseismic data. Attenuation also provides important information for characterizing reservoir structure and changes to it due to HF injections. However, the attenuation effect is typically not considered in microseismic analysis. We have adopted the spectral ratio and centroid-frequency shift methods to estimate the subsurface attenuation (the factor Q−1) in a tight oil reservoir in the Ordos Basin, China. The P- and S-wave attenuations are calculated using the 3C waveform data recorded by a single-well downhole geophone array during a 12-stage HF stimulation. Both methods provide similar results (with differences in Q−1 of absolute values less than 0.010 for P- and S-waves). For individual events, their median Q−1 values calculated from different geophones are selected to represent the average attenuation. Spatiotemporal variations in attenuation are obtained by investigating Q−1 values along propagating rays linking different source-receiver pairs. The Q−1 values derived at different HF stages reveal significant attenuation in the targeted tight sandstone layer (0.030–0.062 for Q−1P and 0.026−0.058 for Q−1S), and the attenuation is apparently increased by fluid injection activities. We explain the sudden decrease in attenuation near the geophone array as a result of high shale content using log data from a horizontal treatment well. The consistency between the Q−1 values and horizontal well-log data, as well as the HF process, indicates the reliability and robustness of the attenuation results. By studying spatiotemporal variations in attenuation, the changes in subsurface structures may be quantitatively characterized, thereby creating a reliable basis for microseismic modeling and data processing and providing additional information on monitoring the HF process.

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