Oil And Gas Migration And Lithologic Accumulation Mechanism Of Wen’an Slope Belt In Ba’xian Depression

Migration is the core issues of the petroleum geology, which run through the geological processes of the oil and gas history. It is the key and difficulties issue that how to predict the dominant migration pathways of hydrocarbon migration.This artical use the GIS platform involves of space parameters of processing and analysis methods,based on the comprehensive analysis of the parameters such as transport system, energy field controlling factors, and we use the information of accessible and reliable from the oil and gas exploration to carry out the research of oil and gas migration characteristics in the Wen’an slop belt, which also can verified the reliability and accuracy of the prediction model.Wen’an slop belt located in the eastern of BaXian depression, the background of structure is a slope which tendency is southeast to northwest. The existing drilling results in the slope show that middle-shallow reservoir sand body have changed quickly in the vertical and horizontal directions, and oil located in different layers, so that reservoir formation conditions and distribution rules are hard to grasp, and it is difficult to. looking for lithologic reservoir. Therefore, the most urgent problem is how to acknowledge major controlling factors of lithologic reservoir accumulation reservoiring pattern and the oil and gas accumulation rules.The major oil and gas migration passways of Wen’an slope belt include:the high permeability sand body and good connectivity consequent faults. The high permeability sand body, consequent connectivity fault and reverse fault constitute to transpotation framework of the slope. Oil and gas migrate along with the nasal shape of YiLunBao structure, the nasal shape structure of ChangFengZhen, the nasal shape structure of ShiGeZhuang and the nasal shape structure of SuQiaoNan to the Updip through the high permeable sand body, and eventually aggregated into block reservoir in the good sealing caused of reverse accumulation, and then along the fault sealing up again oil and gas out of the migration direction.Through the advantage migration pathways of wen’an slope belt from can know that fault-conducting sand body match is an important conduit system of oil and gas in the slope. In the southern slope include the nasal shape structure of YiLunBao and NanMaZhuang region mostly depend on MaXi and WangXianZhuang oil source fault, which vertical conduit and conducting sand body close match the transverse conducting gathered oil and gas, but the closing structures extends long, In the subsags, the hydrocarbon source rocks of the generation of oil and gas through the permeability sandstone transverse lateral petroleum firstly, and because of more sequent and reverse fault, oil and gas migrate along the fault vertical conduit or the fault role and the lateral docking sandstone of disc into sand body continue to migration. Wen’an slope with adjustable fault by the fault to determine the oil and gas has taken to the slopes takeaway from shallow to deep gradually gathered the characteristics of migration. The main controlling factors of oil gas accumulation of Wen’an slope includes nasal shape structure control the oil and gas injection migration to open and close control, fault of hydrocarbon migration and accumulation, gathers, hydrocarbon traps development is the prerequisite, trapping and of the hydrocarbon source rock supporting space.This topic research layer section includes ES2-ED, oil and gas enrichment belt and the bottom up oil and gas filled with degrees in different position performance. Through the research on deposition and the reservoir physical properties, make clear the sand body exhibition cloth law and property distribution law, for oil and gas migration channel simulation advantage to provide high porosity distribution zones. Through to the fault seal ability and connectivity analysis, find out the oil source of slope belt wen faults and fault closeness. Influence of fault sealing the main controlling factors include: a fault of the formation of the stress mechanism, fault of the slope Angle, the divide, faults argillaceous content, faults, two sets of lithology joint relations and pressure system. At present quantitative evaluation method of fault sealing sex basically has:a fault mud ratio (SGR), mudstone daub factor (SSF) can, etc. Wen’an slope belt in the process of the fracture system research found that blocking the ability of the oil and gas downstream fault is poor, and oil and gas filled with degree is not high, reverse fault sealing strong ability of the oil and gas, and oil and gas filled with degrees higher, so in constructing the conduit framework system, we put the downstream fault when connectivity fault treatment, reverse fault closeness do fault treatment.Through the establishment of the quantitative relationship between the various parameters and dominant migration pathways, we can study the hydrocarbon migration paths to achieve the forecast model and the develop related technologies, and make prediction and simulation of oil and gas migration path apply to petroleum reservoir basin Laws and reservoirs, especially in the complex reservoir rock formation evaluation and positioning of the oil exploration.The main reservoirs found in Wen’an slope belt include fault block reservoirs, broken nose reservoirs, lithologic reservoir and fault-Iithology composite reservoir type etc. Wen’an slope belt reservoirs characteristic feature expressed as:an overall structure for the north to west tilt slope, lack of complete anticline structure and reservoir, the main development under the background of slope of the fault block, as well as the broken reservoir structure trap. Oil and gas distribution mainly the fault traps lateral sealing and closed area of control, the oil and gas accumulation degree and fault activities on the strength. Fault blocks are main layer reservoirs, gas and water system is very simple.Through an oil and gas migration of slope belt advantage of channel simulation, determined the work area of exploration zones beneficial lithology. Two sections of the sand sand from the part of the delta depositional system of the delta front facies belt, sand on a section of the braided fluvial river deposits and dongying group of meandering river deposited, and easy to slope belt to parallel, delta front phase out its sand body and pointed channel sand body and lateral margin slope match the tectonic background, to lithologic reservoir formation. From the analysis of the preservation condition, the most favorable to oil and gas accumulation of the percentage of sandstone with<20%most favourable. Integrated structure and the research results of the sedimentary facies, and to select out four favorable exploration target.