Research On Main Controlling Factors Of Natural Gas Accumulation In Dongying Group Of Nanpu Depression

In order to find out the main controlling factors of gas accumulation and distribution in the Dongying group of the of Nanpu depression, this paper through the analysis of the drilled natural gas wells in Dongying group of Nanpu depression,summarized the distribution of natural gas,in the plane the natural gas enrichment in western is better than that in the east in Dongying group of Nanpu,the natural gas enrichment in Nanpu No. 1, No. 5 and Laoyemiao structural is better than that in Nanpu No. 2, No. 3, No. 4 and Gaoshangpu structural,and natural gas is mainly distributed in the vicinity of the fault zone;in the vertical direction, the natural gas enrichment in Ed1 is better than that in Ed2 and Ed3. On the basis of Nanpu Sag existing geological, seismic and drilling data combined with previous research results of Nanpu Sag of Dongying group in natural gas accumulation is related to the source Rock condition, reservoir condition, caprock condition, fault condition and gas trap conditions were studied,analysis the matching relationship between natural gas distribution and accumulation conditions of natural gas, clear the main controlling factors of reservoir forming. The results showed that the main controlling factors of natural gas accumulation in Dongying group of Nanpu depression:(1) Natural gas distribution range is controlled by the transporting capacity of gas-source faults, natural gas in Dongying group of Nanpu depression mainly distributed around the gas-source faults communicate the kind of I hydrocarbon source Rock.(2)Gas accumulation position controlled by caprock integrity and the high ratio sand reservoir,Natural gas easily accumulate in position with high ratio sand reservoir and a better caprock integrity.(3)In the faults concentrating belt, the back- shaped structure is the favorable area for the accumulation of natural gas, and the natural gas is easy to be formed in the inner part or the edge of the back- shaped.(4)Reverse fault block trap is an advantageous type of natural gas accumulation. In clear the main controlling factors of natural gas accumulation to predict and optimize the favorable exploration areas in Dongying group of Nanpu depression, and points out the direction for the natural gas exploration in the next step. Six prediction traps are proposed, which are NP1.13.N-1, NP1.13.N-2, NP4.39-S, NP2.11.N, NP2.5.E and B35x1.S traps, andNP1.13.N-2 trap is considered to be the least of the exploration risk,should be the preferential exploration targets.