摘要
针对四川盆地元坝超深层大气田勘探开发难点,研究超深层生物礁优质储集层发育与成藏富集机理,创立超深层地震勘探、钻完井及测试等技术。通过对晚二叠世等斜缓坡—镶边台地动态沉积演化过程及区域沉积格架的恢复,建立四川盆地元坝地区二叠系长兴组"早滩晚礁、多期叠置、成排成带"的沉积模式,揭示"早期暴露溶蚀、浅埋白云石化形成基质孔隙、液态烃深埋裂解超压造缝"的储集层发育机理,提出"孔缝耦合"控制超深层优质储集层发育的认识。通过油源对比,提出深水陆棚相吴家坪组—大隆组是四川盆地北部地区二叠系主力烃源岩,建立超深层弱变形区"三微输导、近源富集、持续保存"的成藏模式。运用"孔缝双元结构模型"的孔隙结构参数进行地震反演,落实元坝气田高产富集带面积98.5 km^2。创建特种井身结构、发展非常规井身结构,解决多压力系统复杂地层封隔难题,研发出整体式耐高压FF级采气井口及地面安全联动装置。
To solve the difficulties in exploration and development in Yuanba Great Ultra-deep Gas Feild in Sichuan Basin, SW China, the article studies the mechanism of development of quality reef reservoirs gas accumulation and innovates techniques for ultra-deep seismic exploration, drilling, completion and testing. Through the dynamic depositional evolution process of homoelinal ramp-fringed platform and reconstruction of regional depositional framework in the Permian, it is found that the reservoirs in the Changxing Formation of Yuanba area, Sichuan Basin are developed in a pattern of ＂early shoal and late reef, multiple stage stacking, in rows and belts＂, dissolution in early exposure stage and dolomitization during shallow burial give rise to the pores in matrix, overpressure caused by cracking of liquid hydrocarbon during deep burial induces fractures, and coupling of pores and fractures controls the development of ultra-deep high quality reservoirs. From correlation of oil and source rock, it is concluded that the Wujiaping Formation and Dalong Formation of deep-water continental shelf are the major source rocks in the Permian of northern Sichuan Basin. The hydrocarbon accumulation mode in ultra-deep formations of low-deformation zones is characterized by ＂three-micro migration, near-source enrichment, and persistent preservation＂. Through seismic inversion using the pore structure parameters of pore-fracture dual structure model, the high production gas enrichment area in Yuanba gas field is 98.5 km^2. Moreover, special well structure and unconventional well structure were used to deal with multiple pressure systems and sealing of complex formations. A kind of integral, high pressure resistant FF-level gas wellhead and ground safety linkage device was developed to accomplish safe and environmentally friendly gas production.
出处
《石油勘探与开发》
SCIE
EI
CAS
CSCD
北大核心
2018年第1期14-26,共13页
Petroleum Exploration and Development
基金
国家自然科学基金"四川盆地二叠系-三叠系白云岩储层差异演化与油气差异富集机理"(U1663210)
关键词
四川盆地
元坝气田
超深层
长兴组
生物礁
地震勘探
测试技术
Sichuan Basin
Yuanba gas field
ultra-deep formation
Changxing Formation
reef
seismic exploration
testing technology
