Research On Reservior And Distribution Of Oil&Gas Of Oil Ⅰ Of The Member1of Dongying Formation In North Laoyemiao Region, Laoyemiao Oilfield

Laoyemiao oilfield is a inheritant rolling over anticline, located in the northern part of Nanbao depression of the northern part of Huanghua sag, which is a positive second-order tectonic controlled by the Xinanzhuang fracture in north. The main oil formations is Dongying groups, among which, the oil in Dongying group one is the purpose of the present study layer.The oil fields in Dongying group of Laoyemiao oilfield are main fault blocks controlled by the rolling over anticline, which are separated by many faults, the structural feature is quite complicated, the main target formation is delta deposition, the reservoir properties is poor, the differences of reservoir characteristics between different faults are big, the horizontal sand body change quickly, the contradiction in layers is obvious, the oil-water system is complex, the accumulation rule is also complicated, the distinguish between oil and water layer is difficult, the reservoir scale is small,the geological understanding is difficult. So it is necessary to make the research of reservoir characteristics and oil and gas distribution regularity in studying area.Based on the core data, logging data and physical data of the I oil group in Dong1formation, the paper carried out the thin layer division and contrast of86wells in the area, with the marker bed of basalt-basal conglomerate at the top of I oil group in dong1formation and the low-resistivity mud stone at the bottom. It divided Dong1group into there oil groups, in addition the I oil group can be divided into17layers. Besides,14Skeleton contrast profiles are set up in studying area.By means of isochronous stratigraphic framework, combined with the facies signs of rock types and their characters, sedimentary textures and structures, paleontology and well logging, single well facies and profile facies of target formation have been analyzed associating with lithofacies and logging facies, besides, the sedimentary facies plane distribution characteristics and evolution in each small layer have been analyzed according to the thickness of sand body isoline map. The research suggests that the oil group in Dong1formation belongs to fan delta plain and fan delta front and phase depositions, containning sevaral sedimentary microfacies such as underwater distributary channel, subaquatic interdistributary embayments distributary, mouth bar, sand sheet, in which underwater distributary channel and mouth bar are the main reservior sand with Fine sandstone in deposits、high porosity and permeability、good Reservoir property, which indicate it belongs to good sedimentary facies belt. The structure in study area is the clear anticline structure, which is separated by many faults, but the fault activity become weak to the top of anticline, often appears the characteristics of intersection to the anticline axis. Under this situation, the types of sedimentary microfacies are the main factors, which control reservoir sand body of reservoir property. The basic characteristics of reservoir study suggests the sandstone in Dongl formation I oil group is miliary arkose, the maturity of Mineral composition and structure is quite low, the interstitial material mainly is dolomite, secondly is clay matrix, containning a few calcite, The pore type was dominated by intergranular dissolved pore, intragranular dissolved pore, moldic pore and less rock fracture and Particles crack; The pore structure is mainly the mesopore,on the whole,the reservoir of Ed1Ⅰ oil group belongs to the Low permeability and low porosity reservoirs, The sedimentary micro-facies and diageenesis were the main factors of the reservoir physical property.With datas of physical property and log interpretation, macroscopic heterogeneity of Ⅰoil group in Ed1was researched, especially interformational heterogeneity and areal heterogeneity. It is included that the reservior has strong heterogeneity as a whole, belongs to middle porosity and permeability reservoir, the The distribution of sandbody is controlled by sedimentary facies, exhibit from northwest to south, and the sand thickness vary unequally. The sandbody communication along the source direction is good, but perpendicular to the source direction is bad. The distribution of physical property on plane is basically matched to the sand body morphology, and The physical property in the southwest of the study area is better than that in the northeast, and that in thick sandstone place is good relatively.Synthesizes The Above Analysis, the underwater distributary channel in studying area is the main Oil production phase,80%Oil production were focused on the underwater distributary channel sedimentary microfacies phase, whereas the production in mouth bar is low, but some single well in which still has strong ability of oil. All oil groups in Dong1group have oil reservoir distribution, and the average thickness of single reservoir is3.0m. On profile the hydrocarbon distributes in13small layers; on the plane, oil and gas are focused on the main part of rolling anticline, the oil in M27-25、M109×1、M105×1is rich, whereas the oil in flanks M11and M36are Relatively poor.On the whole, Hydrocarbon reservior are mainly controlled by multiple factors such as sedimentary microfacies, permeable sandbody, microtectonics, among which, the favorable facies belt and the permeable sand body are the main controlling factors, the next is the microtectonics, thus favorable sedimentary facies distribution and permeability of sand is an ideal target area for exploration.