Researvoir Geochemical Study Of Katake Uplift And Adjacent Area In Tarim Basin

A total of 73 crude oil and 8 gas samples were selected from Katake Uplift and adjacent areas such as Shuntuoguole Region,west Shuntuoguole-Ka 1 Region,which were used for Fine reservoirs geochemical analysis to contrast with the typical the Ordovician or Cambrian crude oil and gas from Tarim Basin.Oil-oil,gas-gas and oil-source rocks correlation are carried out.Finally the family of crude oils are classified and source rocks of oils and gas are determined.Research has indicated that the geochemical characteristics of crude oil from Katake Uplift is variety.The crude oil composition and typical biomarker series show that there are three oil groups,which originated from Cambrian source rocks,Ordovician source rocks and the Cambrian-Ordovician source rocks.The geochemical characteristics of the crude oil from West Shuntuoguole-Ka 1 Region are similar to the Shuntuoguole Region.Correlation with the typical crude oil samples with Ordovician sources in Tarim Basin reveals that the oil originated from source rocks in the Ordovician.Combining fluid inclusion micro-thermometry with recovering the evolution of the stratigraphic burial as well as thermal histories on samples from Well Shuntuo-1 in Shuntuoguole Region,we determined that there were two stages of hydrocarbon charge in the studied gas reservoirs.The early-stage light oil accumulations were occurring during 435~425Ma(the end of the Early Silurian-the early of the middle Silurian),which was basically consistent with the hydrocarbon accumulation time in the Tahe Oilfield.The light oil originated from source rocks in the Early Ordovician.The studied gas reservoirs were late-stage dry gas accumulations with gas-charging during 12~4Ma,which was approximately the same as the gas accumulation time in Shunnan Region.The dry gas originated from source rocks in the Cambrian.Composition analyses of hydrocarbon and stable carbon isotopes of gas samples in Shuntuoguole-Gucheng region indicate an over-matured dry gas,with carbon isotopic values bigger than-40‰.The gas in Shunguotuole-Gucheng Region originated from source rocks in the Cambrian.By analysis the relation between gas production and fault distribution,the results indicated that faults are the main channels for hydrocarbon migration.The gas production of the gas wells which were close to a fault zone were significantly higher than the gas wells which were far away from the effective pathways.