The Main Controlling Factors Of Reservoir Forming Of Zhujiang Formation In Dongsha Uplift, Pear River Mouth Basin

Dongsha uplift, which is located in east section of central uplift belt in northeast of the pearl river mouth basin, is a large-scale nose-like uplift that distribution north eastwardly and submerge to southwest direction. There are more than 10 oil and gas fields and plenty of hydrocarbon show has been found in Dongsha uplift till now.Especially for limestone reservoir, which mainly distributed in Dongsha uplift, has a great exploration potential. Now, Marine Petroleum Resources is gradually valued,The research of limestone reservoir in Dongsha uplift has a great meaning. Take the Dongsha uplift area of Pearl River Mouth Basin as the research object in this paper.Based on the study of regional geological background and tectono-sedimentary evolution, combing with geological conditions of hydrocarbon pooling and anatomy of typical Oil and Gas Reservoirs in this area, we analyze the main controlling factors of limestone reservoir forming in Dongsha uplift areas.Based on the collected of predecessors' research achievements of Pearl River Mouth Basin in this paper, Research the regional tectonic evolution characters of Dongsha uplift. On the basis of the regional sedimentary background and logging and logging data, Summarizes the regional stratigraphy and sedimentary facies characteristics. Make full use various analysis assay data of dongsha uplift to research the geochemistry characteristics of source rocks, And evaluate the ability of hydrocarbon-generating potential of source rocks further by use of SPI potential index.Application of reservoir microexamination approaches, such as thin section identification of core and cuttings, scanning electron microscopy, Combined with the porosity and permeability data to study the characteristics of the reservoir. On the basis of the original data of drilling, logging, well logging to anatomy the reason which cause the success and failure in typical reservoir exploration in the Dongsha uplift area, And complete the research of comprehensive geological conditions and main control factors with the results in the study area.Through the analysis of regional geological background in the study area, Pearl River Mouth Basin has experienced four stages and multi-stage time evolution process with the control of the degree, direction and the migration of spreading ridgeposition of The expansion of the south China sea. Pearl River Mouth Basin experienced three periods, Which is continental clastic sediment, sea and land transitional facies sediment and Marine facies sediment during Cenozoic era. There are 8 formations in bottom-up process at Dongsha uplift area, which is Shenhu Formation, Wenchang Formation, Enping Formation, Zhuhai Formation, Zhujiang Formation, Hanjiang Formation, Yuehai Formation, Wanshan Formation.Oil and gas in limestone reservoir of Dongsha uplift mainly comes from Enping and Wenchang Formation continental hydrocarbon source rocks which distributed in the surrounding sag, the Hydrocarbon is resourceful. The calculation results of SPI potential index of hydrocarbon source rock show that, SPI value of the Most hydrocarbon source rocks of is between 5~10, achieve a strong ability of hydrocarbon charging.Zhujiang Formation main development two types of reservoir, limestone with biological framework structure and crumb structure in Dongsha uplift. Reservoir physical property characteristics shows that, reservoir in Liuhua region with high porosity and good pore and permeability relations, reservoir in Liuhua region is most development and Lufeng region take second place. Reservoir is nondevelopment in Huizhou region because of strong cementationThrough the analysis of the factors of hydrocarbon accumulation in Zhujiang Formation, Dongsha uplift, Consider that the hydrocarbon in the study area are derived mainly from Wenchang and Enping Formation hydrocarbon source rocks of surrounding sag. Dongsha uplift area has two phases of oil and gas filling into reservoir, hydrocarbon migration path, the reef flat facies limestone reservoir and the effective configuration of trap common control hydrocarbon accumulation. Fault and limestone fracture is the main channels for vertical hydrocarbon migration, and lateral migration path of hydrocarbon mainly controlled by the oil and gas flotage and the capillary resistance in transport layer.