Petroleum controlling theory of Lunnan paleohigh and its buried hill pool exploration technology,Tarim Basin

Aimed at the difficulties in the petroleum exploration and development,the controlling function of Lunnan paleohigh on the hydrocarbon accumulation of Ordovician buried hill is studied based on new theories and technologies.A theoretical system is established of the paleohigh controlling petroleum accumulation and the buried hill being wholly petroliferous with local enrichment.The paleohigh is the main direction that the hydrocarbon migrated to.It controls the up growth of karst crack-cavity type reservoir,the formation of the fault transportation system and the multiperiod accumulation of oil and gas.The paper presents a new model of karst quasi-layered reservoir of Lunnan residual paleohigh,indicating that the hydrocarbon under the control of karst reservoir is accumulated within the 150m of the surface layer of buried hill.A series of exploration and development technologies for buried hill pools of the kind are also developed,including the reservoir 3D seismic forecast and acidizing fracturing improvement,the heterogeneous carbonate well point choice,and the irregular well pattern development,etc.