渤海M油田注采系统渗流场特征及布井优化

Research of Injection-production System Seepage Field Characteristics and Well Spacing Optimization in Bohai M Oilfield

针对渤海常规稀油油田缺少相关水平井开发理论的问题,以渤海M油田为研究对象,利用保角变换与势叠加原理,研究了水平井采油–直井注水一注一采模式(I)、水平井采油–水平井注水一注一采模式(II)、水平井采油–直井注水一注二采模式(III)及水平井采油–水平井注水一注二采模式(IV)等4种典型水平井注采模式的势场方程、无因次产量表达式、等势线分布图和无因次产量变化图版。理论分析结果表明:生产井与注水井正对时,I^III类模式产量最大;水平井井网交错时,IV类模式产量在注采井距小于水平段半长时最小,在注采井距大于水平段半长时最大,且注采井距等于其实际水平段长度时,两生产井之间最优距离为0.5~1.0倍水平段半长。油田实例分析表明:获得的理论产量与油井实际产量具有一致性。

Aimed at the lacks of the related theory and experience about horizontal well development Bohai conventional thin oilfields. The four typical horizontal well injection-production systemswere studied with the conformal transforation and poten-tial superposition principle：one vertical well injection and one horizontal well production（I）,one horizontal well injection and one horizontal well production（II）,one vertical well injection and two horizontal wells production（III）,and one horizontal well injection and two horizontal wells production（IV）in M Oilfield,we established the potential field equation,the corre-sponding dimensionless productivity equation,and draw the equipotential line maps＆dimensionless production change chart by conformal mapping and potential superposition principle. Theoretical analysis results show that：the production of I～III injection-production system is the most when producing wells directly face injecting wells. Nevertheless the production of IV injection-production system is the most of them when horizontal well spacing staggers,and the optimum distance is 0.5～1.0 times the half length of horizontal segment while injector-producer spacing equals the length of actual horizontal section. The oilfield application instances indicate that analysis results of theoretical production are consistent with the real production.