塔里木盆地库车坳陷克拉苏构造带—秋里塔格构造带白垩系巴什基奇克组深层、高产储层特征及控制因素

Comparative study on deep and high yielding reservoir characteristics and controlling factors of Cretaceous Bashijiqike Formation in Kelasu structural belt and Qiulitage structural belt of Kuqa Depression,Tarim Basin

为了进一步扩大塔里木盆地库车坳陷白垩系储层的勘探成果,明确储层的形成机理,基于钻井、录井、普通薄片、铸体薄片、粒度分析、X⁃射线衍射和物性分析等资料,系统开展了塔里木盆地库车坳陷克拉苏构造带和秋里塔格构造带白垩系巴什基奇克组储层特征及控制因素对比研究。秋里塔格地区白垩系储层粒级粗、长石含量低、岩屑含量高(以沉积岩岩屑为主);填隙物含量略低、杂基含量高、胶结物含量低;物性相对好,为低孔特低渗储层,具有排驱压力较高、孔喉半径中—小、细—微细喉的特征;压实作用中等,胶结作用中等,溶蚀作用较强,有利于储层孔隙的保存。克拉苏构造带白垩系储层粒级细,以中、细砂岩为主,长石含量高,岩屑含量低,少量沉积岩岩屑;填隙物总量略高,杂基含量低,胶结致密;面孔率普遍较低,微裂缝普遍;物性差,为超低孔超低渗储层,具有排驱压力高、孔喉半径特小、微细喉的特征;压实作用强、胶结致密、溶蚀作用弱,裂缝对储层孔隙的贡献有限,却大大改善了储层的渗透性能。

In order to further expand the exploration results of Cretaceous reservoirs in Kuqa Depression,clarify formation mechanism of reservoirs,based on data,such as drilling,logging,ordinary slice,casting thin sec⁃tions,granularity analysis,X-ray diffraction analysis and physical properties,reservoir characteristics and con⁃trolling factors of Cretaceous Bashijiqike Formation in Kelasu structural belt and Qiulitage structural belt in Kuqa Depression of Tarim Basin have been systematically studied.The Cretaceous reservoirs in Qiulitage area are coarse in grain size,low in feldspar content,high in rock debris content especially in sedimentary rock de⁃bris;the content of interstitial material is slightly lower,the content of matrix is higher and the content of ce⁃ment is lower;they have good physical properties and are low porosity and low permeability reservoirs with the characteristics of high displacement pressure,medium-small pore throat radius and fine-microfine throat;medi⁃um compaction,medium cementation and strong dissolution are beneficial to the preservation of reservoir pores.The Cretaceous reservoirs in Kelasu structural belt are fine in grain size,mainly composed of medium and fine sandstones,with high feldspar content and low rock debris content,and a few sedimentary rock debris;the to⁃tal amount of interstitial material is slightly higher,the content of matrix is low,and the cementation is com⁃pact;surface porosity is generally low and microcracks are common;they have bad physical properties and are ultra-low porosity and ultra-low permeability reservoirs with the characteristics of high displacement pressure,extremely small pore throat radius and microfine throat;besides strong compaction,tight cementation and weak dissolution,though fractures have limited contributions to reservoir pores,they greatly improve reservoir per⁃meability.