The Study Of The Reservoir Forming Conditions For Yitong Basin Northwestern Edge Luxiang-Chaluhe

Yitong Basin runs along the north-east in central Jilin Province, located between Changchun and Jilin,which is long and narrow down the Fault depression basin in Jilin Province. Its complex geological conditions, the thickness of hydrocarbon source rocks, good quality, reservoir development, the latter part of the basin evolution squeezing action make Yitong Basin oil and gas resources become rich basins, large exploration potential.Because of the northwestern margin of Luxiang- ChaluRiver, Yitong Basin seismic data acquisition for the late 1990 s, data quality is poor. With the improvement in the level of exploration, data quality of old exploration area is insufficient to meet the modern exploration requirements, so look for new analytical techniques, the application of new technology to old exploration area so that data were reinterpreted again Yitong Basin exploration discovery could play a decisive role. Because of Yitong Basin northwest margin of Luxiang- ChaluRiver Fault depression is complex structure, formation dip change, low signal to noise ratio of seismic data, poor image quality, there are some difficulties in fan portrayed,work experience in reservoir characterization lacks. To solve the above problems, this paper applys new technologies VSP seismic zero bias, palaeogeomorphology analysis technology and seismic data and log data to identify the combination of structural styles, fan-body portrayed predict favorable reservoir, further study the northwestern margin of Yitong Basin’s Luxiang- Chalu River accumulation conditions. The results show that depression ChaluRiver’s Wangchang District District northwestern margin squeeze areas affected by strike-slip tectonic stress having good reservoir structure background, structural zone near the northwestern margin of Fort Xin’an depression, developmental Shuangyang group Kut Sheling group and three sets of source rocks, organic maturity, at maturity- high maturity. General development of the region Wangchang District delta sand, shallow depth of less than 3000 m, has good reservoir conditions. Regulating the family for good regional mudstone cap, inner layer of the three segments and Wangchang District Sec Wangchang District group as well direct mudstone caprock, Multiple fracture of the lower part of the communication source rocks, excellent oil source conditions, swells to form a reservoir lithology- structural reservoirs, reservoir reflects the distant source, reservoir characteristics of two phases;ChaluRiver northwestern margin Chang40-Chang48 well area, Shuangyang formation as the main source rocks, hydrocarbon source rocks buried deep hydrocarbon source rock maturity and reach maturity- over mature stage, the development of large-scale inshore Shuangyang Sec subaqueous fan, sandstone reservoir, reservoir quality is good, is a good reservoir, Lake Shuangyang group into three sections form a large set of gray-black shale is a good regional cap, the extension phase of oil and gas generated by the fault migration to Shuangyang Sec nearshore subaqueous fan, forming fault- lithologic reservoir, reservoir reflects the near-source, multi-phase reservoir characteristics. Luxiang faulted off more favorable oil and gas accumulation, mainly for Great Southern fold belt sag off the northwestern margin of the leading edge portion, possession of a controlled thrust limit extension was long and narrow shape, Luxiang Fault depression source rocks and Shuangyang Shuangyang formation group of three sections, Sheling set period of hydrocarbon source rocks reached the threshold of hydrocarbon source rocks in humus-based, Shuangyang formation basal conglomerate, Shuangyang Formation, a thick layer of sandstone and Sheling group for a period of sandstone reservoirs layer, mainly oil and gas transport in communication source rock and reservoir fracture system, Sheling group located in close proximity to a thick layer of shale source rock lithology changes due to the formation of lateral Fengdang, thus forming rock and reservoir reservoirs of oil and gas reservoirs; Shuangyang nearshore subaqueous fan body development, large-scale, but by the depth of the impact bias Shuangyang reservoir conditions, trap types are mainly the fault- lithologic traps.Luxiang in northwestern margin of Yitong Basin- ChaluRiver comprehensive analysis of hydrocarbon accumulation on the geological conditions, the system summary Luxiang-ChaluRiver distribution of oil and gas, Luxiang- ChaluRiver Fault depression strata have more oil, buried deep reservoir characteristics, showing an overall distribution of oil and gas vertical overlay lace pattern. Preliminary evaluation of the northwestern margin of Luxiang, Yitong Basin- ChaluRiver depression has 50 million tons of oil and gas exploration potential,which is the next step in Yitong Basin oil and gas exploration and development focus area band.