苏里格分支水平井难度最大的地方在于分支井眼,分支井眼首次将大斜度井段和水平段设计为全裸眼,针对苏里格气田分支井眼斜井段和水平段处于同一裸眼段的技术难题,室内研发了强抑制性有机-无机盐低伤害钻井（完井）液体系,并在桃7-14-18H分支井和桃7-15-20H分支井的分支井眼成功试验应用.室内和现场试验结果表明,该体系能有效解决气井水平井斜井段和水平段同处于裸眼段情况下的的泥页岩井壁失稳、气层保护、高摩阻大扭矩、井眼净化、携砂悬砂等一系列技术难题.该体系抑制性强,其页岩一次回收率达到了97.2％,二次回收率达90.3％;体系利于保护产层,对盒7和盒8产层岩心的平均伤害率为10.60％,属于低伤害.钻井液优良的综合性能保障了1742m装有裸眼封隔器的套管完井管串直接穿越裸眼斜井段安全下至水平段的预定位置.

During the exploitation process of unconventional adsorbed gas reservoirs,as formation pressure decreases,adsorbed gas will be desorbed and make adsorbed layer decrease and free gas space increase.At present,the material balance equation considering adsorbed layer volume variation has not been established and has not been applied to research the influence of adsorbed layer volume variation and density on adsorbed gas reservoir reserves.This paper firstly established new material balance equation considering the adsorbed layer volume variation.The application cases proved the applicability and reliability of this equation,and it is cognized that adsorbed layer volume variation and density have greater influence on natural gas reserves estimation.

With the impact of geology,well patterns,allocation and fluid properties,it is impossible to achievecomplete equilibrium displacement for actual reservoirs.However,a relatively high balance displacement must bemaximally pursued so as to attain maximum oil recovery efficiency for heterogeneous reservoirs.According to thenumerical simulation researches,well spacing and allocation have greatly influenced on equilibrium displacementof injection-production well group,and the same geological model has a dimensionless equilibrium displacementwell spacing and production;finally permeability range has an effect on the dimensionless equilibrium displacementwell spacing and production,then optimal well spacing and allocation is determined,which supplies a theoreticalreference for balance displacement effects of injection well group.