Study On The Controlling Factors On Hydrocarbon Accumulation In The Lixian Slope

Lixian slope have found almost 100 million tons of oil reserves, in recent years it’s exploration entered into a confused stage and there is no great achivement any more, this is due to the unclear of the migration systems. First this article synthetically uses geology, geochemistry, geophysics and other kinds of material to explicit the relationship between reservoir and source, then do in-depth research on migration systems, finally make out the advantage hydrocarbon migration path.Found O il of lixian slope can be divided into five types. O il source correlation is evalued with Geochemical indicatiors comprehensively, northen oil source correlation is complex, hydrocarbon comes from Es₁下、Es3上、Es3下、Es4 and mixtion of Es₁下 and Es4 source rock. Hydrocarbon of South slope only comes from Es₁下 source rock.Migration system elements have been quantified evaluation and made clear of pool- forming period and nowadays migration systems growing fea tures. By Es₁ and sand Es₂ sand connectivity analysis, we know that Es₁5 and Es₂下 braided river delta sand is the main skeleton of sand. Through exploring the activity and sealing property of faults with pool- forming period, C larified oil-source faults transportation ability and oil-control faults controlling features. By means of the fluid potential and overpressure analysis, combining with the character of structual ridges, we consider that structual ridges are the adavantage hydrocarbon migration path. Comprehensive analysis of the relationship between sand 、fault and structural ridge and conducting performance, it shows faults and sand is configured as an effective migration system, faults play a major role in northern slope; sand play a major effect in southern slopes. oil and gas move mainly along structure structual ridge.The source rock 、 transporting system 、structual ridges and sand are the main controlling factors, combined with hydrocarbon migration and accumulation s imulation experiments, sums up different reservoirs forming modes in both north and south,so that to predict the exploration prospects of Es₁⁵ and Es₂^下.