摘要
为了研究低渗/致密油藏分段压裂水平井的开采机理和渗流规律,通过建造高压仓、密封和改进多通道电阻率测量方法,研发了大型露头岩样高压物理模拟实验系统。通过分段压裂水平井物理模型的岩样筛选、模型的制作和封装、模型抽真空饱和以及有效驱动的物理模拟评价等方法的研究,建立了分段压裂水平井物理模拟实验方法。进一步结合低渗/致密油藏非线性渗流油藏数值模拟软件研究了低渗/致密油藏分段压裂水平井渗流规律。研究结果表明:在相同驱替压差下,分段压裂水平井的压力梯度值要比普通水平井的压力梯度值高,且随着压裂裂缝半缝长的增加,压力梯度值也增加;当水平井水平段长度一定时,储层渗透率越低,分段压裂水平井的最佳分段数越多;当储层渗透率一定时,水平井水平段长度越长,水平井压裂的最佳段数也越多,最佳裂缝半缝长反而呈现减小的趋势;对于低渗/致密油藏分段压裂水平井开采来说,对产量最为敏感的是压裂段数,其次是裂缝半缝长,而裂缝导流能力最为不敏感。
This study investigates the exploration and porous flow mechanisms in multi-stage fractured horizontal wells （MSFHWs） in low permeability/tight oil reservoirs （LPTORs）. A high-pressure physical simulation system for large-scale outcrops is developed by constructing a high-pressure chamber, sealing and improving multi-channel resistivity measurement techniques. A physical simula- tion method for MSFHWs is established based on simulation and evaluation of the physical model in core sample selection, produc- tion and packaging, vacuum saturation, and effective driving. Further, porous flow pattern of MSFHWs in LPTORs are studied u- sing a nonlinear porous flow simulation software. Under the same displacement pressure, the pressure gradient in MSFHWs is grea- ter than that in ordinary wells and grows with increasing half-length of the fractures. When the length of a MSFHW is fixed, the LPTOR with lower permeability requires a greater number of optimal fracturing segments; when the permeability of a LPTOR is fixed, the optimal number of fractured segments increases with the horizontal length of the MSFHW but the half-length of optimal fractures shows a declining tendency. For exploitation of MSFHWs in LPTORs, the number of fractured segments is most sensitive to well production, followed by the half-length of the fractures, and fracture conductivity the last.
出处
《石油学报》
EI
CAS
CSCD
北大核心
2014年第1期85-92,共8页
Acta Petrolei Sinica
基金
国家重大科技专项(2011ZX05013-006)
中国石油天然气股份有限公司重点科技攻关项目(2011B-1203)资助
关键词
低渗
致密油藏
水平井
分段压裂
物理模拟
数值模拟
渗流规律
low permeability/tight oil reservoirs
horizontal well
multi-staged fracturing
physical simulation
numerical simalation porous flow law
