摘要
川东地区上二叠统长兴组生物礁礁体经历了海底、潮坪、陆上、浅-中埋藏和深埋藏成岩环境,而礁间相和非礁相沉积直接从海底成岩环境进入浅-中和深埋藏成岩环境。礁灰岩中的大量原生孔隙被海底和埋藏成岩环境中多期胶结物充填而丧失殆尽。礁间生物屑灰泥沉积物微孔隙在压实过程中逐渐消失。礁体的白云岩主体是埋藏成岩环境中形成的,一般孔、渗性良好。礁顶发育2—7m厚的潮坪白云岩,则孔、渗性很差。
During the period of Late Permian, transgression from east to west occurred inSichuan and its adjacent areas. The Upper Permian Changxing Formation reefs in fustSichuan were pinnacle and patch reefs which climbed on carbonate ramp with tragres-sion. The Changxing reefs underwent five diagenetic environments, i. e. the sea floor,reef ialand tidal flat, subaerial, shallow to moderate burial and deep burial diagenetic envi-ronments. However, interreefs and non--reefS had never exposed and undergone meteoricdiagenesis. They underwent from sea floor to shallow-moderate burial and deep burial dia-genetjc environments. A lot of primary pores of reef rocks (shelter and growth framework voids, intrabiotic pores, interbreccia cavities, etc.) were almost filled by multi-phasecements of sea floor and burial diagenesis. Interreef biogenic debris and lime mud depositshad many micropores that were progressively vanished during burial compression process.Most of the dolomites of a reef body were formed by the replacement of compaction fluidswhich converged towards and through reefs in burial diagenetic environmemt and havegood porosity and permeability. The main reservoir spaces are late solution pores andintercrystalline pores.
出处
《石油与天然气地质》
EI
CAS
CSCD
北大核心
1991年第4期364-375,T001,T002,共14页
Oil & Gas Geology
