致密储层水力压裂裂缝发育程度定量表征对致密储层压裂开发优化具有重要意义,关于复杂裂缝发育程度定量表征指标多忽略改造区内裂缝发育情况.提出新的复杂裂缝发育程度定量表征指标,即拟裂缝密度,并以HN油田AP区块为例,分析复杂裂缝发育程度影响因素,且将其运用于指导实际矿场井.研究发现,随着应力差增加,拟裂缝密度先增加后降低.储层渗透率增加,拟裂缝密度降低,且降低趋势由慢变快.在HN油田AP区块所受应力、天然裂缝发育情况下(应力差10 MPa,两组天然裂缝同时发育),当射孔角度为0°、压裂液黏度为0.4 mPa·s时,能够获得最佳的压裂改造效果.将以上参数优选结果运用于指导矿场实际APX直井压裂,APX直井产量递减趋势得到了有效缓解,且在压裂12个月有效期内增油量1 900 t.
Quantitative characterization and influencing factors analysis of hydraulic fracture in tight reservoir
The quantitative characterization of the hydraulic fractures is of great significance to the fracturing optimization in tight reservoirs.At present,the quantitative characterization index of the complex fractures mostly ignores the fractures in the reconstruction area.Therefore,the article proposes a new quantitative characterization index for the complex fractures:pseudo fracture density.And then taking the AP block of HN oilfield as an example,the factors affecting the complex fractures are analyzed,and it is applied to guide actual field wells.It is found that as the stress difference increases,the pseudo fractures density first increases and then decreases.The permeability of the reservoir increases,the pseudo fractures density decreases,and the decreasing trend changes from slow to fast.Under the stress and natu-ral fracture conditions in the AP block of HN oilfield(The stress difference is 10 MPa,and two sets of natural frac-tures are developed),the optimal fracturing simulation effect can be achieved when the perforation angle is 0° and the fractu-ring fluid viscosity is 0.4 mPa·s.The optimization results of the above parameters are applied to guide the hydraulic fractu-ring of the APX vertical well.The production decreasing trend of APX vertical well was effectively alleviated,and the oil production increased by 1 900 t within the 12 months.
tight reservoircomplex fracturethe quantitative characterizationfactor analysispseudo fracture density
万方数据
维普
