松辽盆地汪家屯气田气藏富集特征及挖潜技术对策

Enrichment tCharacteristics and Technical Countermeasures for Tapping Potential in Gas Reservoirs of Wangjiatun Gas Field in Songliao Basin

典型复杂断块致密砂岩气藏具有砂体规模小且分布零散、储层物性差、单井井控储量低的特点。松辽盆地汪家屯气田处于开发中后期,大部分气井已进入低产、低效阶段,储量挖潜及经济有效开发难度大。为解决气田开发瓶颈难题,从断裂、砂体及成藏等角度开展了气藏富集特征研究。结果表明:通源断裂控制气藏的纵向发育部位和横向展布;砂体发育规模、厚度及物性决定气藏富集程度;断层和砂体的空间分布对气藏具有分隔作用;油气差异运聚控制流体空间分布。为提高气田整体的储量动用程度,在气藏地质研究的基础上,结合气田开发特征,提出5项挖潜的技术对策:精细构造与储层描述,优选挖潜部位加密布井;老井措施改造,挖掘增产潜力;利用氮气欠平衡钻井技术,有效保护储层;增压开采试验,提高流体流动能力、延续气井生命周期;开展水平井及老井侧钻水平井试验。

Typical complex fault block tight sandstone gas reservoirs are characterized by small scale and scattered distribution of sand bodies,poor reservoir physical properties,and low single well controlled reserves.Wangjiatun Gas Field in Songliao Basin is in the middle and later stages of development.Most gas wells have entered the stage of low production and low efficiency,and it is difficult to tap the potential of reserves and develop economically and effectively.To solve the bottleneck difficulty of the gas field development,enrichment characteristics of the gas reservoirs are studied from the perspectives of faults,sand bodies and hydrocarbon accumulation.The results show that the connecting oil source faults control the vertical development position and horizontal distribution of the gas reservoirs.The development scale,thickness and physical properties of the sand bodies determine the enrichment degree of the gas reservoirs.The spatial distribution of faults and sand bodies can separate the gas reservoirs.The differential migration and accumulation of oil and gas controls the spatial distribution of fluid.In order to improve the overall reserve producing degree of the gas field,five technical countermeasures for tapping the potential are proposed based on the geological research of the gas reservoir combined with.the development characteristics of the gas field:fine structure and reservoir description,well pattern thickening at selected positions with potential tapping;reconstruction of old wells by measures and tap the potential of increasing production;application of nitrogen underbalanced drlling technology to effective reservoir protection;boosting production test for improving fluid flow ability and prolonging the life cycle of gas wells;tests of horizontal wells and side tracking horizontal well in old wells.