The Cambrian platform bank or shore reservoir is an important petroleum exploration target in Sichuan Basin,so it is important for the oil and gas exploration to accurately predict the occurrence,reservoir performance and distribution patterns of the sedimentary facies. The study of Cambrian palaeogeography and tectonic-depositional environment is the key to reservoir prediction. Based on the field measurement of profiles,drilling and logging analysis and seismic data,with the thought of mobilistic tectonics-palaeogeography, the maps of the Cambrian tectonic-depositional environment,which can reflect the palaeogeography and basin evolution in Sichuan Basin, have been drawn by analyzing the sedimentary geology conditions,regional well profiles,stratigraphic thickness and sedimentary facies and so on. From the maps it can be seen that it was relatively higher in the west and north,lower in the east and south of Sichuan Basin during the Cambrian. The shore land and tidal flat facies were developed in the western basin; and inner gentle slope,platform and platform marginal shoal facies were developed in the middle and eastern of study area. The response of sedimentary facies evolution in space and time is: the restricted platform in the Meishucun Age of Early Cambrian→clastic platform and deep basin in the Qiongzhusi Age of Early Cambrian → shore-mixd platform in the Canglangpu Age of Early Cambrian→carbonate ramp in the Longwangmiao Age of the Early Cambrian → the evaporation and limited rimmed platform in the Douposi Age of the Middle Cambrian → the mature rimmed platform in the Xixiangchi Age of the Middle-Late Cambrian. Among the above,the Qiongzhusi Formation was a thick bed of source rocks;the Longwangmiao and Xixiangchi Formations were benefied to forming carbonate reservoirs;gypsum rocks formed in the Longwangmiao and the Douposi Formations were good caps.
Corresponding Authors:
He Dengfa,born in 1967,obtained his Ph.D. degree from Research Institute of Exploration and Development, PetroChina, in 1995.Now he is a professor of China University of Geosciences(Beijing). E-mail: hedengfa282@263.net.
About author: Li Jiao,born in 1990,is a master degree candidate of China University of Geosciences(Beijing). Now she is mainly engaged in researches on the tectonic characteristics of depositional basins. E-mail: 916630094@qq.com.
Cite this article:
. Palaeogeography and tectonic-depositional environment evolution of the Cambrian in Sichuan Basin and adjacent areas[J]. JOPC, 2014, 16(4): 441-460.
. Palaeogeography and tectonic-depositional environment evolution of the Cambrian in Sichuan Basin and adjacent areas[J]. JOPC, 2014, 16(4): 441-460.