Integrated Study Of Reservoir Geology Of Karamay Formation In Liudong District

Junggar basin, one of large oil and gas basins in China northwest. Major tectonic units in China-part of the Junggar block. The Tianshan orogenic belt, East and west Junggar and Altai mountains surrounded the Hercynian fold. An area of130,900square kilometers. Above Junggar Triassic basin is Mesozoic and Cenozoic unified continental sedimentary basins. Composite overlay with the underlying Paleozoic Partition of Sea-land transition of sedimentary basins. therefore, This is a large composite superimposed basin.Karamay Oilfield Location at the Junggar Basin mountains south of Zaire. Oil zone Development by oil region broken. Karamay-Urho regicide cover across the central fault zone. Section westward tilt. Slow on the steep lower. According to fracture of the cutting conditions, Field is divided into one, two, three, four, five, six, seven, eight, nine block area and a number of development blocks. Six districts in the north-east Karamay Oilfield. hanging wall of Karamay fault belt. foot wall of westen Bai-Bai fault belt. The district six can be further divided into Western six, Eastern six And Central six. Among them, six Eastern Karamay Formation reservoir surrounded by faults cutting, possession of a structural oil controlled by the faults. Structural position in the Junggar Basin northwest edge of the g-black big plate on the fracture area of approximately11km2. Karamay Formation unconformity deposits in the Carboniferous above, showing the distribution of things strip, gradually deepening to the southeast from the northwest half anticline, the burial depth of about200m to800m between. Karamay Formation reservoir is located in grams-black and large faults on the disk, their structural form at the bottom of a formed by the basal bulge slope zone, the structural highs located at6226wells in northern The overall tilt to the southeast and southwest in both directions, but the two wings and asymmetric, southeast wing steeper inclination of between10°-20°; the southwest wing is relatively flat, the inclination of2-5°.According to lithology, outcrop, seismic and drilling data, and other aspects of data analysis, the formation of the bottom-up development of the six Eastern Carboniferous (C), grams group (T2k1), g on the group (T2k2), white alkaliBeach group (T3b), eight Bay group (Jib), ancient Qi group (J3q),, the Cretaceous Tugulu group (K1t) Quaternary stratigraphy and surface deposition. Among them, the main oil-bearing strata of the Triassic g group, g on the group and Jurassic Qi ancient group, within the local area, the Carboniferous reservoirs are well developed.Karamay Formation is divided into a medium-term cycles, g on the group complete the mid-cycle composed of g under the rising half cycle composed; cycle will be characterized by identifying the ultra-short-term Karamay Formation is divided into14small, each layerby a super-short cycle. After a superimposed combination of ultra-short-term cycles, the Karamay Formation is divided into six sand group:S1, S3, S4, S5, S6, S7, each sand group composed of a short-term cycles. Among them, the S7is divided into four small, S6, is divided into three small, S5is divided into two small layers, S4, is divided into two small layers, the S3is divided into two small layers, S1is divided into a small layer.Six Eastern Karamay group, overlapping the top of the shell of deposition of the next overlying Carboniferous basement uneven weathering, is a west to east to southeast dipping monoclinal structure, the overall topography of the west is the old mountain foothills east gradual transition from the lake basinancient climate is semi-arid climate type. Six East coring wells in the region of the core observation and logging analysis, can identify labor, the district Karamay development of underwater distributary channel, debris flow deposits, the former Delta mud in sedimentary microfacies, six kinds of sedimentary microfacies mutually combined to form the fan delta front and prodelta mud subfacies.Depositional environment and provenance of the main factors of influence and control the type of rock. The six Eastern sedimentary micro analysis, the development of Karamay fan delta deposition. Fan-delta deposition rate is relatively fast, relatively coarse lithology, conglomerate, sandy conglomerate, pebbly sandstone, sandstone and mudstone the Karamay main rock types, but mainly as a reservoir rock type conglomerate and sandy conglomerate and sandstone.Analyzed by scanning electron microscopy, sheets and cast thin section images, the pore type the Karamay reservoirs of the study area matrilysin Kong secondary porosity intergranular dissolution pores, intragranular dissolved pores and micro-cracks, and primarilyintergranular dissolution pores and matrilysin Kong-based content in more than90%. Pore Types in the hole-hole type. The overall throat thin throat level, the pore throat combination type in the hole-the type of macroporous thin throat. According to the characteristics of the13samples the mercury intrusion curve and related parameters, summed up a total of three types of pore structure type. Sandstone and sandy conglomerate reservoir good physical properties, porosity distribution is relatively concentrated, although the difference of porosity between the layers, but in general more homogeneous. The permeability distribution of a wide range of penetration is better than sandstone, conglomerate and sandy conglomerate basically belong-high porosity and high permeability layer. A whole showed a gradual deterioration trend from west to east, properties, good physical properties in some areas of central and southeast. The six Eastern Karamay group, the reservoir is the main sand body of underwater distributary channel deposits and debris flow deposits.Karamay Formation reservoir distribution in the whole district. Higher in the structure of the Ministry of reservoir Fengdu and thickness; the lower part of the construct, the reservoir is less and the thickness of the thin border of the reservoir sand bodies pinch-out lines, faults and oil-water interface. Show the distribution of tectonic and sedimentary micro-control reservoir in the form.7sand group, the main reservoir the S7sand group.Triassic Karamay Formation in the study area, get understanding and conclusions are as follows:1.According to the theory of high resolution sequence stratigraphy, six Eastern Karamay group is divided into six sand group and14small.2.Karamay different stages of sedimentary evolution is obvious, overall the eastern water depth, western shallow, physical geography from the western, the S7S6of base level rise of the S5of the S4of the datum period of decline, S3of S1of base level rise.3. the the Karamay group of the study area for the fan-delta deposition, a total of identified fan delta front and the front fan delta2sub-phase debris flow deposits, the deposition of underwater distributary channel, mouth bar deposition, tributaries between Bay deposition distal bar deposits and prodelta mud microfacies6microfacies.4. Target layer is the high porosity and the permeability reservoirs, pore throat combination type holes-big holes-the type of fine jets.5.Block decreased from west to east, fluid viscosity, the northeast and southeast of the block has a higher residual oil saturation, you can expand the edge region as a reference.