The Hydrocarbon Source Rock Evaluation And Resource Potential Analysis Of Dingqinghu Formation In Lunpola Basin

Lunpola basin is located in the central of Tibet and it’s area is3600km2.Thebasin is a Cenozoic continental strike-slip fault basin which is developed in theBangonghu-Nujiang suture zone. Compare with the large numbers of tertiarycontinental basin in Tibet,Lunpola basin has good petroleum geological conditionsand high exploration level and has obtained industrial flows.This studycomprehensively analysis the chatacteristics of Lunpola basin dingqinghu formationhydrocarbon source rock,especially the oilshale.However,this study hold the differentundersranding of the petroleum geological conditions and resource potential ofdingqinghu formation in the upper of the basin.The essay choose sedimentary andpetroleum geological conditions of Dingqinghu formation to be the researchobject,through the sedimentalogy and organic geochemistry analysis,the study obtainsome knowledge as follow:1.Lunpola basin ha“sseparated belts in north-south trend and separated blocks inthe east-west trends”tectonic framework.The basin experienced two majar stages:faultdepression stage and depression stage，corresponding to Niubao and Dingqinghuformation sendimentary period.The half deep lacustrine facies-deep lacustrine faciesmudstone,shale and oilshale is the major hydrocarbon source rock of Dingqinghuformation.2. Comprehensive evaluation reveals that hydrocarbon source rock in firstmember of Dingqinghu formation is the main source rock of Dingqinghu formationand its belong to good classes while the second and third member source rock belongto invalid to poor source rock.The type of source rock organic matter is mainly typeⅠ-Ⅱ1.The first member source rock is in low mature stage and The second and thirdmembers source rock is in low immature stage.The distribution area of Dingqinghuformation is426km2and the thick of it is200m.3.The oilshale of Dingqinghu formation can be seen in thePapa,Lunpori,Jiangriacuo area. Comprehensive evaluation reveals that the major minerals of oilshale is clay minerals and quartz mineral.The oilshale has high oilcontent,high ash content and low total sulfur contant characteristics.The oilshalebelong to good to perfect oilshale, the main type of organic matter isⅠ-Ⅱ1and mostoilshale are immature-low mature. The source of oilshale organic matter iscomplex,contains both terrestrial higher plant and aquatic plankton.The depositionalenvironment is strong reduction and high salinity environment.The distribution areaof oilshale is374km2and the thick of it is69.5m.4.This study use organic carbon and volume method to estimate the Dingqinghupetroleum and oilshale resource quantity.Through calculation, speculate of oilresource volume is11.34million ton and speculate of gas resource volume is226.8million cubic meters. speculate of oilshale and shale oil resource volume is67.58billion ton and4.859billion ton.