The Characters And Distribution Rules Of He8Member Reservoir Of Su43Block

The Sulige gas field is the largest gas fields discovered in China up to now. Withan abundant resource extent, it is an important gas source of the West-East GasTransmission Project. SU43block, located in western area I, is a chief block in theexploration strategy:” Mainly Focus on The Western Area I”. So the reservoircharacters and distribution rules should be deeply researched to enhancing theefficiency of the exploration and exploitationBased on the data of cores, well-logging and experimental results, well-logginginterpretation and the research of lithology, physical properties, pore-structures andreservoir space types is completed. The heterogeneity is evaluated, and the reservoirclassification and distribution is accomplished on the base of the determination of thereservior lower limit.The main rocks type of Su43block is quartzose sandstone, secondly the lithicquartz sandstone and greywacke. The sandstone (reservoir intervals) is identified bythe means of cross plot and multivariate statistics on the basis of the log responses.The sandstone is categorized into quartzose standstone and lithic quartz sandstone,greywacke by components. The well-logging parameters are researched to establishthe interpretation models of shale content, porosity, permeability and water saturation.The reservoir of S43block, He8member is a extra-low to low porosity andextra-low permeability reservoir. The lower segment, especially lower segment1,arethe best intervals on the aspects of physical properties. The permeability is positivelycorrelated with porosity. Physical properties of quartzose standstone are much betterthan lithic quartz sandstone. The pore space mainly includes emposieu andintercrystal micropores. Intrusive mercury curves can be devided into4kinds, andtheⅠ、Ⅱ curves shows satisfactory physical properties while theⅢ、Ⅳ curves presentspoor. And the former kind is much more common than the latter.Planar distribution and longitudinal section of sandbody show that the thicknessand continuity of lower segment of He8are superior to upper segment. The continuityof sandbody on the N-S-trending is better than E-W.As a whole, the heterogeneity ofwork area is serious.The permeability rhythm includes the positive rhythm, thereverse rhythm and the compound ones.Statistics of traditional permeability heterogeneity parameters and research of Lorenrz curves both show that heterogeneityof each segmentof He8member is strong.The main components of barreier beds and interbeds are argillaceous. Betweenupper and lower segment of He8, between the first and second segment of lower He8,and inside the second segment of lower He8there are always barriers beds, which arestable on the surface and thick on the section. Inside the lower segment of He8, thereare always interbeds which are limited distributed in the plane.The integrated study by the method of statistics and intrusive mercury dataindicate that the lower limit of porosity and permeability of reservoir in study area arerespectively5%and0.1×10-3μm2.According to the flow unit theory,theparameters:RQI,FZI,displacement pressure, porosity and permeability are chosen asindexes to divide the reservoir into Ⅰ、Ⅱ、Ⅲ、Ⅳ classes by K-algorithm arithmeticmethod. The single well reservoir evaluation and the reservoir distribution on bothsectional and plane were researched. Ⅰclass reservoir is local and discontinuous,while the Ⅱ and Ⅲ class reservoir are widely developed. The reservoir of lowersegment of He8is better than the upper one.