Fracture Network Volume Fracturing Technology in High‐temperature Hard Formation of Hot Dry Rock

2021 ◽  
Vol 95 (6) ◽  
pp. 1828-1834
Author(s):  
Zuo CHEN ◽  
Guoqing XU ◽  
Jian ZHOU ◽  
Jiankun LIU
Keyword(s):  
High Temperature ◽  
Fracture Network ◽  
Hot Dry Rock ◽  
Hard Formation ◽  
Volume Fracturing

scholarly journals Description of Fracture Network of Hydraulic Fracturing Vertical Wells in Unconventional Reservoirs

2021 ◽  
Vol 9 ◽  
Author(s):  
Jinghua Liu ◽  
Mingjing Lu ◽  
Guanglong Sheng
Keyword(s):  
Flow Rate ◽  
Early Stage ◽  
Fractal Theory ◽  
Fracture Network ◽  
Unconventional Reservoirs ◽  
Box Dimension ◽  
Vertical Wells ◽  
Reservoir Permeability ◽  
Fractal Index ◽  
Volume Fracturing

Based on the distribution of complex fractures after volume fracturing in unconventional reservoirs, the fractal theory is used to describe the distribution of volume fracture network in unconventional reservoirs. The method for calculating the fractal parameters of the fracture network is given. The box dimension method is used to analyze a fracturing core, and the fractal dimension is calculated. The fractal index of fracture network in fracturing vertical wells are also firstly calculated by introducing an analysis method. On this basis, the conventional dual-media model and the fractal dual-media model are compared, and the distribution of reservoir permeability and porosity are analyzed. The results show that the fractal porosity/permeability can be used to describe the reservoir physical properties more accurately. At the same time, the flow rate calculating by conventional dual-media model and the fractal dual-media model were calculated and compared. The comparative analysis found that the flow rate calculated by the conventional dual-media model was relatively high in the early stage, but the flow rate was not much different in the later stage. The research results provide certain guiding significance for the description of fracture network of volume fracturing vertical well in unconventional reservoirs.

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.

Deformation and instability failure of borehole at high temperature and high pressure in Hot Dry Rock exploitation

2015 ◽  
Vol 77 ◽  
pp. 159-165 ◽  
Author(s):  
Yangsheng Zhao ◽  
Zijun Feng ◽  
Baoping Xi ◽  
Zhijun Wan ◽  
Dong Yang ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Hot Dry Rock

Optimal Design of Proppant Supported Fracture Length in Tight Oil Volume Fracturing

2015 ◽  
Vol 1092-1093 ◽  
pp. 1436-1439
Author(s):  
Yuan Zhou ◽  
De Sheng Zhou
Keyword(s):  
Hydraulic Fracturing ◽  
Oil And Gas ◽  
Fracture Network ◽  
Tight Oil ◽  
Fracture Length ◽  
Production History ◽  
Oil And Gas Resources ◽  
Oil Seepage ◽  
Volume Fracturing ◽  
Effective Development

Hydraulic fracturing technology has promoted the economic and effective development of unconventional oil and gas resources in North America, the fracture network by horizontal well hydraulic fracturing can significantly improve tight oil seepage environment and improve production rate. Taking a typical well A in Erdos dense oil basin as an example, supported fracture length is studied by matching its production history. By comparing with its actual micro seismic mapping, the proppant supported fracture length is optimized. The paper provides a technical method to optimize supported half fracture length, which is helpful in practical operation.

scholarly journals Numerical Simulation on Heat Recovery Efficiency of Different Working Fluids in High-Temperature Rock Mass

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Xu Dong ◽  
Haozhe Geng ◽  
Guan Hao ◽  
Pan Li ◽  
Yi Teng ◽  
...  
Keyword(s):  
Rock Mass ◽  
High Temperature ◽  
Heat Recovery ◽  
Injection Pressure ◽  
Recovery Process ◽  
Thermal Recovery ◽  
Heat Extraction ◽  
Recovery Efficiency ◽  
Working Fluids ◽  
Hot Dry Rock

It is of great significance for the sustainable development of global energy to develop hot dry rock (HDR) geothermal resources by using enhanced geothermal system (EGS) technology. Different working fluids in EGS have different heat recovery efficiencies. Therefore, this paper takes water and CO2 as the heat-carrying media and establishes a thermal hydraulic mechanical coupling model to simulate the heat recovery process in high-temperature rock mass. By considering the different confining pressures, rock temperature, and injection pressure, the advantages of H2O-EGS and CO2-EGS are obtained. The results show that with the increase of confining pressure, the heat recovery efficiency of water is significantly higher than that of CO2, but at higher reservoir temperature, CO2 has more advantages as a heat-carrying medium. The net heat extraction rate will increase with the increase of injection pressure, which indicates that the mass flow rate plays a leading role in the heat recovery process and increases the injection pressure of fluid which is more conducive to the thermal recovery of EGS. This study will provide a technical guidance for thermal energy exploitation of hot dry rock under different geological conditions.

scholarly journals Method for Calculating Productivity of Water Imbibition Based on Volume Fracturing Stimulations of Low Permeability Reservoirs

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Lisha Zhao ◽  
Xin Li ◽  
Shuhong Wu ◽  
Zhongbao Wu ◽  
Min Tong
Keyword(s):  
Oil Recovery ◽  
Fractured Reservoirs ◽  
Three Dimensional ◽  
Fracture Network ◽  
Economic Feasibility ◽  
Low Permeability ◽  
Diffusivity Coefficient ◽  
Two Phase ◽  
Water Imbibition ◽  
Volume Fracturing

Spontaneous water imbibition is an important mechanism in water-wet fractured reservoirs. For volume-fractured reservoirs, to evaluate the oil productivity and oil recovery through water counter-current imbibition, we propose an analytical method for optimizing the reservoir volume fracturing scheme. Based on the two-phase fluid flow differential equation for capillary force, a three-dimensional water imbibition productivity equation is derived analytically. The equation for the water imbibition productivity considering the fracture network is obtained. A numerical model is constructed to verify the validity of the average capillary diffusivity coefficient and the results of the analytical model. By applying this method to a low permeability reservoir, after volume fracturing and waterflooding huff and puff, the relationship between the tenth year’s oil recovery and oil production rate and the length, width, and density of the fracture network is predicted, which gives an optimization of the field fracturing construction scale. The results show that the length and width of the fracture network should be no less than 50% of the well spacing and row spacing to obtain a reasonable production. Considering the fracturing technique and economic feasibility, the higher the density of the fracture network, the better the production obtained. Through hydraulic volume fracturing and waterflooding huff and puff, water imbibition is brought into full play and the 10 year oil recovery is increased by 6%–8% in this area.

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