THE COUPLING OF STRIKE SLIP MOVEMENT AND DELTA DEPOSITION AND ITS CONTROLLING OVER HYDROCARBON ACCUMULATION: A CASE FROM NORTH SAKHALIN BASIN IN RUSSIA

Based on the tectonic evolution, sediment filling characteristics and the distribution pattern of oil and gas fields in the North Sakhalin Basin of Russia, we discussed in this paper the main controlling factors of oil and gas accumulation. It is found that the spatial distribution of oil and gas fields in the basin is in a zoning pattern in north-south direction. Oil decreases while gas increases from the north to south. Vertically, oil and gas occur in higher horizon in the north but lower horizon in the south. On the scale of oil and gas accumulation, the fields on land are usually smaller than those in the sea. The distribution of oil and gas is mainly controlled by the coupling of strike slip faults and deltaic deposition. The strike slip movement and deltaic deposition in different period control the distribution of source rocks, which result in the distribution of oil in the north and gas in the south; The migration of the three stages of deltaic deposits with the strike slip movement caused the vertical oil and gas occurence, which is higher in the north and lower in the south. Strike slip faults are also the factor which controls trap scale and preservation conditions of oil and gas fields, making the oil and gas fields smaller on land but bigger in the sea. According to the above analysis, this paper suggests that the eastern area of the North Sakhalin Basin is more favorable for oil and gas exploration.