考虑人工裂缝的单井数值模拟技术的应用

常规数值模拟网格技术在描述经过压裂增产的油气井时存在不足，很少考虑裂缝的几何形态以及裂缝导流能力对油气井生产动态的影响。考虑人工裂缝的单井数值模拟网格技术（PEBI）可以更加准确地评价压裂增产油气井单井控制储量、单井控制泄流半径，预测油井的生产动态以及对裂缝效果进行敏感性分析。文章结合试井分析，确定了裂缝几何尺寸和裂缝导流能力，对低渗油田某井建立了数值模拟模型。在较高的历史拟合精度上，对油井进行了动态预测，同时分析了裂缝半长和裂缝导流能力对油井生产动态指标的敏感性。结果表明该井单井控制泄流半径约为400 m，单井控制原油储量41.9×10⁴t。增加裂缝半长会增加累积产油量，但是随着裂缝半长的增加，累积产油量的增加幅度就越来越小。增加裂缝渗透率能较大地提高原油的稳产年限和累积产油量，当裂缝渗透率达到5 μm^２后，增加裂缝渗透率对油井生产动态指标的改善不明显。

APPLICATION OF SINGLE WELL NUMERICAL SIMULATION WITH HYDRAULIC FRACTURE IN CONSIDERATION

Conventional numerical simulation network technology has certain shortcomings when it is used to describe oil and gas producers stimulated by fracturing, because the influences of fracture geometries and flow conductivities on the performances of oil and gas wells are seldom taken into consideration. Single well numerical simulation network technology with hydraulic fractures in consideration (PEBI) can more accurately evaluate the reserves and drainage radius under single well control after fracturing stimulation, predict the performances of oil and gas wells, and analyzes the sensitivity of fractures. In combination with the well test analysis, the fracture geometry and conductivity are calculated and a numerical simulator is built for a real well in a low permeability oilfield. Based on the history match with relatively high accuracy, the performances of the well are predicted and the sensitivity of fracture half length and conductivity to production performance indexes of the well are analyzed. The calculation results show that the drainage radius controlled by this well is about 400 m and the oil reserves controlled by the well are 419,000 tons. The cumulative crude output will increase with the increasing fracture half length, but the incremental cumulative crude output will be in decline. The years of stable production and cumulative crude output will increase by a relatively big margin along with the increasing fracture permeability, but the improvement of production performance indexes of the well along with the increasing fracture permeability is not evident after the fracture permeability reaches 5 μm2.