Evolution, Lithofacies Paleogeography of Chinese Marine Craton Basins and Types of Giant Carbonate Fields
Zhang, Guangya¹; Liu, Wei¹; Deng, Shenghui¹; Zhang, Lei¹; Guo, Yanru¹; Xie, Zengye¹; Yu, Bingsong²; Hu, Wangshui³
¹RIPED of Petrochina, CNPC, Beijing, China.
²China University of Geosciences, Beijing, China.
³Yangtze University, Jingzhou, China.
Tarim basin, Sichuan basin and Ordos basin are major marine basins developed in China, which formed respectively in Tarim, Yangtze and North China small-scale cratons. Two extended-convergent tectonic cycles, Mesoproterozoic (or Neoproterozoic)- Devonian and Carboniferous- Triassic, which these three basins experienced responds to the development of Paleo-Asian Ocean and Tethys Ocean tectonic domain. Marine deposit basins formed in the first cycle, moreover, basin prototype and paleotectonic framework was controlled by the activity of adjacent plates. The isochronous stratigraphic framework shows that Cambrian is correlatable in three basins while Ordovician is not.
Lithofacies paleogeography research based on these three basins illustrates that sedimentary facies belt of carbonate platforms is characterized by small scale, strong differentiation and rapid lateral variation, which results from intense activity of Chinese small craton. Three types of carbonate platform margin were identified including fault controlling steep slope margin, deposit controlling steep slope margin and palaeohigh controlling ramp margin. Sedimentary differentiation is distinguished in platform and characterized by intra-shelf basin and intraplatform bank. Carbonate bank developed within the platform and at platform margin are potential area of reservoir.
Source rocks are mainly formed in cratonic marginal extensional depression, intracraton extensional depression, cratonic marginal flexural depression and cratonic marginal faulted basin. Major marine basins experienced multiple phase deformation and generally covered by other kinds of basins. Interaction of uplift, resolution and fracture created four types of karst reservoirs including buried hill karst reservoir, bed parallel karst reservoir, interlamination karst reservoir and hydrothermal solution reservoir.
Multi-stages of hydrocarbon accumulation are common in marine deposit basins in China and the hydrocarbon phase is complicated. The giant oil and gas fields can be classified as the buried hill, reef and beach complex and weathering crust type. Oil and gas distribution is controlled by uplift, reef and beach complex, karst area, fracture belt is the abundance zone.
AAPG Search and Discovery Article #90155©2012 AAPG International Conference & Exhibition, Singapore, 16-19 September 2012