Exploration breakthrough and significance of the Ordovician fault controlled karst oil and gas reservoir in Well Luotan 1 in Maigaiti slope,Tarim Basin
A new breakthrough has been made in the Ordovician carbonate rocks in Well Luotan 1 in Maigaiti slope,Tarim Basin,marking the first exploration breakthrough of a new type of Ordovician fault controlled karst carbonate oil and gas reservoirs in Maigaiti slope,which is a major strategic replacement field in the slope zone.Combined with the regional well,logging,and seismic data,the laboratory test data of core samples in wells including Luotan 1 is comprehensively analyzed to further understand the hydrocarbon accumulation conditions of the Ordovician carbonate rocks in Maigaiti slope.The study results show that the development of the Ordovician fault controlled karst carbonate reservoirs in Maigaiti slope was mainly related to strike slip fault activity,which was one of the three main reservoir formation modes in Maigaiti slope.The discovered oil and gas in Maigaiti slope were all supplied by source rock in the Cambrian Yuertus Formation,and the paleo basement structure controlled the deposition and distribution of the Lower Cambrian source rock.In the slope zone,three stages of hydrocarbon charging and accumulation occurred in the Caledonian,Hercynian-Indosinian,and Himalayan periods.The composite hydrocarbon accumulation was jointly controlled by source rock,paleo tectonic evolution,and faults connecting source rock,while the hydrocarbon enrichment layers and oil/gas reservoir properties were determined by the stages of fault activity and formations cut faults.The strike slip faults were well developed in the Ordovician in Maigaiti slope,and they controlled the distribution of fault controlled karst carbonate reservoirs and oil and gas reservoirs,with a cumulative extension distance of more than 1000 km,showing clear zoning characteristics on the plane,large resource volume,high feasibility for well deployment,and huge exploration potential,which is a major practical field for discovering large-scale oil and gas reserves and achieving strategic replacement in the southwestern Tarim Basin.
万方数据
维普
