深层岩石二次人工致裂缝效果影响因素分析

针对深层岩石二次人工致裂缝过程中影响因素复杂、施工技术界限模糊等问题，以泌阳凹陷赵安鼻状构造 HTY 三段地层为例，采用二维二相油藏 － 裂缝系统模型结合正交试验方法，定量分析含水饱和度、地层压力、有效渗透率、压裂规模等因素对岩石二次人工致裂缝效果的影响，确定深层岩石二次人工致裂缝施工过程中的关键因素，确立施工技术界限。结果表明: 岩石二次人工致裂缝效果与地层压力、储层渗透率、施工规模、地层含油饱和度及油层有效厚度成正比，影响该区块二次人工致裂缝效果的主要因素为含水饱和度、有效渗透率、地层压力和人工致裂缝长度; 岩石二次致缝技术界限为地层压力保持水平 ＞ 70% 、含水饱和度≤50% 、有效渗透率≥0. 5 × 10^ － 3μm^2。以此作为该区块人工致裂缝选井选层依据，配套施工工艺，现场单井二次人工致裂缝效果良好。

Analysis on factors of influences on secondary artificial fracturing effect on deep rock

Aiming at the problems of complicated influencing factors，indistinct construction technical boundaries，etc. during the secondary artificial fracturing made on deep rock，the influences from the factors of water saturation，formation pressure，effective permeability，fracturing scale，etc. on the secondary artificial fracturing of rock are quantitatively analyzed herein with 2 － D two-phase reservoir-fracture system model combined with orthogonal test method by taking the third stratum of THY formation in Zhanoan Nosing Structure of Biyang Depression，and then the key factors during the construction of the secondary artificial fracturing of rock as well as the relevant construction technical boundaries are determined. The result shows that the secondary artificial fracturing effect is directly proportional to the formation pressure，reservoir permeability，construction scale，saturation of oil bearing formation and the effective thickness of oil reservoir，while the main factors to impact the secondary artificial fracturing effect on the oilfield block are the water saturation，effective permeability，formation pressure and the artificial fracturing length. The technical boundaries of the secondary artificial fracturing of rock are as follows: formation pressure maintenance level of ＞ 70% ，water saturation of ≤50% and effective permeability of ≥0. 5 × 10 ^－ 3μm^2. By which，the basis for the selection of well and layer is made for the artificial fracturing，thus better effects of both the matching construction technologies and the secondary artificial fracturing of the single well in site are obtained.