天然气工业2018，Vol.38Issue(5)：71-76,6.DOI:10.3787/j.issn.1000-0976.2018.05.008
石英砂用于页岩气储层压裂的经济适应性
Economic adaptability of quartz sand for shale gas reservoir fracturing
摘要
Abstract
In the Changning–Weiyuan area of the Sichuan Basin, 40～70 mesh ceramsite that can keep high flow conductivity at high closure pressure is always used as the main proppant in the fracturing of shale gas reservoirs the minimum principal stress of which ranges between 44 and 68 MPa, but its consumption and cost are high. To reduce the cost of proppant, the flow conductivity required to support the fractures in the reservoirs was demonstrated by means of numerical reservoir simulation. Then, the effective stress of reservoir on the proppant, the loading rate of effective stress and the proppant placement concentration were analyzed by using the analysis results of shale gas well production and the simulation results of hydraulic fractures. Finally, the experimental method suitable for the flow conductivity of proppant used in the shale gas well fracturing in the study area was developed and the flow conductivity of quartz sand and its effect on the productivity were evaluated. Furthermore, this method was used for the screening and field test of proppant. The following results were obtained. First, when the matrix permeability of shale is lower than 6.0×10-4 m D, the production requirement can be satisfied as long as the flow capacity of main fractures and branch fractures are 0.8-1 D·cm and 0.05-0.10 D·cm, respectively. Second, when main fractures are vertical to the minimum principal stress and branch fractures are vertical to main fractures, the maximum effective stress of shale reservoirs on the proppant in the main fractures is 54 MPa and that in the branch fractures is about 69 MPa. Third, the experimental method for evaluating standard proppant flow conductivity is modified by setting the stress loading rate at 1.0 MPa/min, the proppant placement concentration at 2.5 kg/m2 and the maximum loading pressure at 70 MPa. And fourth, the 70/140 mesh quartz sands are selected as the optimum proppant for shale gas well fracturing in the study area. The application in 4 wells on two pads in shows that single-section gas production rate is not changed obviously and single-well proppant cost is reduced by CNY 0.6–1 million when the ratio of quartz sand is increased from 30％ to 7080％. And the cost may be cut further if quartz sand is acquired from local markets. In conclusion, the study results provide a technical support for cost reduction by replacing ceramsite with quartz sand in the tight oil/gas reservoirs the matrix permeability of which is extremely low.关键词
页岩气/储集层/石英砂/陶粒/替代实验/加载速度/高应力/长宁—威远地区/降低成本Key words
Shale gas/Reservoir/Quartz sand/Ceramsite/Replacement experiment/Loading rate/High stress/Changning–Weiyuan area/Cost reduction引用本文复制引用
杨立峰,田助红,朱仲义,严星明,易新斌,段贵府,蒙传幼,邹雨时..石英砂用于页岩气储层压裂的经济适应性[J].天然气工业,2018,38(5):71-76,6.基金项目
国家科技重大专项"大型油气田及煤层气开发"项目"储层改造新工艺、新技术" (编号:2016ZX05023-005). （编号:2016ZX05023-005）
