气藏型储气库是天然气储存的主要设施,库址筛选是气藏型储气库建设过程中的一个重要环节,本文根据长庆气区六年多的岩性气藏储气库库址评价筛选及建设运行实践经验,经过梳理总结,从地理位置、圈闭评价、储层物性及构造特征等关键因素进行库址筛选方法探讨,并通过该方法对已投入运行的S储气库实际情况进行分析,初步形成了一套适合岩性气藏储气库库址筛选方法.

苏南区块是低渗、低压、低丰度的岩性气藏,储层非均质性强,常规的单声波时差计算孔隙度法受泥质分布形式及砂岩压实程度的影响,难以求得地层真实孔隙度.从2018年开始,苏南区块开始应用中子-密度曲线交会计算孔隙度.中子和密度测井对泥质及油气的影响反映比较灵敏,中子-密度曲线交会方法可计算出经过泥质校正以后的有效孔隙度.通过和岩心分析孔隙度进行对比,利用中子-密度曲线交会方法计算的孔隙度与岩心分析孔隙度更加吻合,较单声波时差计算的孔隙度更能真实反映低-特低孔储层的孔隙度,测井处理解释精度大幅提高.应用该方法计算的含气指数比利用声波时差的计算结果更能准确地反映储层的含气性和生产能力,为压裂段的选取提供更好的指导.

苏南区块属于低孔、低渗、低压、低丰度的致密岩性气藏,储层非均质性强,孔隙结构复杂.孔隙度由于受岩性和孔隙结构的影响,骨架值不确定,很难用定值来表示,声波测井用传统的威里公式计算孔隙度方法难以准确求得地层真实孔隙度.根据声波测井原理以及岩石响应特征,并结合本区和邻区岩心分析数据,首先利用声波时差和岩心分析孔隙度回归公式计算孔隙度,然后根据泥质含量的不同,在岩心回归公式的基础上对泥质较重的层段进行了泥质校正,消除了由于泥质含量的影响导致的孔隙度计算误差.实际应用表明,利用该方法计算的孔隙度与岩心分析结果吻合较好,可以更真实地反映地层的储层特征和生产能力.

鄂尔多斯盆地陇东地区长 7 段致密油储层岩性变化快、井控程度低、单砂体厚度小、砂体横向连续性差且纵向上分布不稳定,水平井随钻地质导向难度较大,砂体钻遇率偏低.针对上述难点,根据地质特征及开发要求,采用地质建模的方法沿砂体展布方向设计水平井井轨迹靶点,为水平井钻进提供依据;根据区域地层对比结果,结合导眼井目的层段测井曲线特征确定导向标志层;在造斜段导向过程中,利用随钻测井曲线特征结合录井资料识别标志层,预测着陆点位置及距离并调整钻井造斜率,保证井轨迹精准入靶;在水平段导向过程中,根据随钻伽马正演及伽马成像反演结果控制井轨迹,确保井轨迹在目的层段中穿行.形成了钻前地质设计、在造斜段确定曲率、在水平段调整井轨迹的水平井钻井全周期地质导向工作流程.应用结果表明:该地质导向技术适用于陇东地区水平井钻井,能够有效指导水平井钻进并提高储层钻遇率.

针对靖边气田气井作业和生产过程中,由于水基工作液侵入或生产中地层水、凝析液在井底聚集,使井筒附近储层含水饱和度上升,导致储层气相渗透率降低,气井生产能力变差的情况,通过开展毛细管自吸率、毛细管自吸量分析,进一步深化了对储层水锁效应的认识,并结合平面径向渗流模型和实例分析,基本掌握了水锁对靖边气田气井产能的影响.

Horizontal well three-dimensional development is a new type of gas field development model in recent years, mainly used in the gas fields of reservoir multilayer development, continuous distribution, vertical spacing and flat structure. It is a effective way to improve the development of low permeability reservoir and improve comprehensive economic benefits. Based on the research of seismic and geology, a great quantity of logging data in detail that the horizontal well three-dimensional development block selection principle, technical measures and results, put forward new ideas for the efficient development of Changqing gas reservoir multilayer development block.

长庆气区苏里格气田目前正处于快速上产阶段,选择一个合理的开发模式对其发展有着重要的意义.通过对苏里格气田A区地质资料的深入研究、分析,针对储层发育特点,设计了丛式井组多井型结合的开发模式,并在近几年的实践中取得了显著的效果,为苏里格气田实现少投入、多产出,提高经济效益,实现科学高效开发提供了一种思路.

伴随着靖边气田的规模开发,地震技术也得到了广泛应用,从最初的二维地震测线、连井十字地震测线、非纵地震测线、VSP地震测线到三维地震技术的应用.针对靖边气田A区主力储层薄、非均质性强、小幅度构造发育的特点,实施三维地震40km2,通过日臻完善的三维地震处理技术,预测前石炭纪古地貌形态和主力储层的展布规律,为A井区的整体部署、高效开发提供依据.

The theory of oil originated from deep of the earth considered that oil/gas,like the metal mineral deposits,is the product of degasification within the earth.The geological evolution history of an oil-bearing basin is in response to the earth surface uplift and subsiding and the degasification of the earth's outer core,which reveals the deep structure property of oil-bearing basin.Oil/gas formed from degasification of the earth during the Cenozoic shows characteristics of post-hydrothermal process.Oil/gas dominated by vertical migration is normally accumulated at structural traps and related stratigraphic and lithologic traps,which had closed relationship with neotectonics.Such a theory can be applied to searching for new oil/gas reservoirs.China's oil-bearing basins are characterized by deep burial basement and thick sedimentary strata,which indicate that new oil/gas reservoirs could be found from the strata under the discovered oil/gas pools to the basement.Structural fractured oil/gas reservoirs would be the main targets for exploration in areas with active neotectonics,deep brittle rocks and good cap rocks.The deep seismic survey should be the main method for exploration of them.However,the traditional seismic survey is helpless for detection of deep faults and rock bodies with high porosity and highly fractured belts.Such non-traditional seismic prospecting methods as telemetry,geochemistry,tensor analysis,radioassay and structural configuration modeling,etc.could also be used for it as necessary.

靖边气田试井解释主要应用基础模型进行解释,对试井软件中的扩展模型应用较少,本文应用2-Φ径向复合模型和双层双渗模型对实际工作中遇到的复杂试井曲线进行了完美拟合,并结合地质情况验证解释结果的准确性,为今后试井解释工作提供参考。