The Developing Rule Of Delta-Forward Creeping Turbidite Sand Body And Its Oil-Gas Accumulation Relationship Of Sha 3 Member In Huimin Depression

Based on the theory of tectonic geology, sedimentology, high resolution sequence stratigraphy and dynamics of petroleum accumulation formation, many aspects about Jishan Sand Body of Sha 3 Member in Huimin Depression are studied carefully, such as its tectonic character and evolution, sedimentary system, sand body genesis, pool-forming pattern, and etc., combined with many kinds of technical approach. There are main conclusions and views in this thesis as follows.1. The tectonic dynamic mechanism of Jishan Sand Body is analyzed tentatively. It is found there are three quick sediment periods, i.e. the sediment period of Sha 3 Member, Dongying Formation, and Minghuazhen formation and Quaternary. The tectonic depression is dominant before Dongying Movement, and then the load depression becomes gradually the main depression. There are 4 periods in the evolution progress of Huimin Depression, i.e. the sediment period of Kongdian Formation and Sha 4 Member, Sha 3 Member and Sha 2 Member, Sha 1 Member and Dongying Formation, and Late Tertiary. The research result of fault movement rate shows that the intensity of fault movement rate in Dongying Period is more than that in Sha 1 Period.2. It is advanced that a delta-creeping turbidite system exists in Jishan Sand Body according to a research result of characters of rock, sedimentary structure, grain fineness distribution, seismic face and well logging curve. This delta-creeping turbidite system includes 5 genetic types and each of this creeping turbidite consists of 4 type's sedimentary matter. There are 6 delta-creeping turbidite with different forming time in Jishan Sand Body. The main distribution area of delta-creeping turbidite lies in an area from Well Tian 14 to Well Sahng 15 and in an area between Well Xia 90 with Well Xia 5.3. The high resolution sequence framework has been built up in the area of Jishan Sand Body. One of the second grade sequences and four of the third grade sequence hasbeen distinguished. There are 6 associate sequences developed in Jishan Sand Body. The delta-creeping turbudite mainly distribute in Ps4, Ps5 and Ps6 associate sequence.4. The formation condition of oil and gas accumulation is concluded in detail. It is put forward that there 3 patterns of accumulation formation in Jishan Sand Body, including lateral migration accumulation, vertical migration accumulation and composite migration accumulation. The types of oil and gas accumulation include 3 kinds, structure, rock and structure-rock, and the type of rock exist in third grade slpoe-break, and the other two develop in second grade slpoe-break.5. The next favorable exploration targets are pointed out in Jishan Sand Body, including terbidite in Tianjia, sand lens in Mengsi Low Uplift and many kings of sand traps in Shang 64 Fault Zone.