库车坳陷克深油气田低孔裂缝性气藏压降曲线分析方法及其应用

库车坳陷克深油气田目的层巴什基奇克组储层埋深大,高温高压,天然裂缝发育,属超深高温高压气藏。但是由于钻井过程中钻井液对储层伤害严重,井况复杂,测试资料录取困难,缺乏必要的储层参数,亟需加深对储层的认识。研究发现,大量的酸压施工压降曲线没有得到有效分析和利用。利用压降曲线建立了井底压差与产能关系图版,用以准确判断储层真实物性,消除地层伤害带来的影响。首次利用压降曲线计算储层渗透率,为渗透率模型地质建模提供参数,建立渗透率、米采气指数、裂缝密度三者之间的关系式,反演测试井段裂缝发育程度,给油基钻井液成像测井裂缝解释提供参考。按照单井渗透率和裂缝发育程度,预测区块内临井的储层发育特征,对储层改造进行指导并预测 产能。

Pressure-Decline Curve Analysis Method and Its Application in Low-Porosity Fractured Gas Reservoir in Keshen Oil & Gas Field, Kuqa Depression

Bashijiqike Formation of Keshen oil and gas field target layer in Kuqa Depression features in big reservoir depth, high temperature and high pressure, and natural fracture development. It is an ultra-deep, high-pressure and high temperature gas reservoir. However, due to severe damage of drilling fluid to reservoir during drilling process and complicated well conditions, well testing data are difficult to be acquired and there are insufficient necessary reservoir parameters. It is urgently needed to deepen recognition of the reservoir. Study showed that numerous acidification pressure-decline curves could not be effectively analyzed and used. Pressure-decline curve was used to establish the relationship chart of bottom hole pressure difference and productivity, to accurately judge real reservoir physical properties, and eliminate influence resulting from formation damage. Pressure-decline curve was firstly used to calculate reservoir permeability, provide parameters for geological modeling of permeability models, establish relationship among permeability, gas productivity index per meter, invert fracture development degree of testing well section, and be reference to oil-base drilling fluid imaging logging fracture interpretation. Based on single-well permeability and fracture development degree, reservoir development features near the well within blocks were predicted, which guided reservoir transformation and predict productivity.