The Description Reservoir Of Chang6 In HC37 Well Area

Well HC37 is a typical oil and gas enrichment zone in the FH exploration area in the southeast of the Ordos Basin.With the improvement of geological understanding of low-permeability reservoirs and a variety of collaborative exploration techniques,great progress has been made in recent years.The exploratory well in the target formation has achieved high oil test and high production,which indicates that the Chang6 oil layer in this good area has good exploration and development potential.However,due to the low degree of exploration in this area,the low density of exploratory wells,the lack of various geological data,analysis,and testing,and other data,the understanding of the characteristics of the reservoir is unclear,which affects the geological evaluation and development plan of the reservoir to a certain extent.Formulate.Also,low-permeability tight clastic reservoirs have complex geological characteristics,poor reservoir physical properties,and strong spatial heterogeneity,which leads to spatial uncertainty in the location of oil and gas enrichment,making the overall prediction of high-quality reservoirs difficult.Early research models aimed at the static characteristics of the reservoir can no longer meet the needs of further exploration and development of the reservoir.It is urgent to supplement various new well data in time.According to the feedback of the previous geological understanding and the error of the geological model based on the production performance of the reservoir stage,The geological model was revised to deepen the geological understanding and lay the foundation for the future exploration and development of the Chang6 reservoir.Based on the collection and sorting of the geological and drilling data of 27 wells drilled,this paper selects typical sedimentary structure feature exploration wells for drilling core observations,and uses core physical property analysis,casting thin section identification,particle size testing,clay mineral X-ray diffraction,and other data to compare the Chang6Reservoir evaluation;application of reservoir fluid,well logging,pressure test,and oil test data to evaluate the heterogeneity,sensitivity and seepage characteristics of Chang6 reservoir;combined with various reservoir characteristics,further analysis of reservoir control factors,The geological reserves of HC37 well area were estimated.The results show that the structure is simple westward tilt single slope,east high west low,the development of differential pressure effect formed by the near east-west nasal bulging structure.The sedimentary phase-type is the turbid flow sedimentary sub-phase in the semi-deep lake phase.On the whole,the sand body connectivity is better in the near north-south-west,and the river is extended from north to south-west.The three-stack extension group reservoir in the study area is mainly gray granulated long stone sandstone,low mineral maturity,high structural maturity,strong rock formation,non-homogeneity of the reservoir,sensitivity is weak acid sensitivity,weak water sensitivity,weak alkali sensitivity,and medium-weak salt sensitivity,medium-strong speed sensitivity.Comprehensive evaluation of Chang6 reservoirs,it is considered that reservoir types are distributed from ultra-low permeable to dense layers,mainly IVa-type reservoirs,for ultra-low seepage-ultra-low seepage reservoirs,reservoirs have high binding water saturation and high residual oil saturation,at the same time Due to the relatively large volume of the visual hole throat,resulting in reduced oil drive efficiency,it is recommended to add active agents when filling water later,the reservoir is rocky reservoir,its distribution is mainly controlled by rock and material,high-quality reservoirs are mainly developed in the turbid watercourse sedimentation,on the plane is ribbon Distribution,north-east-south-west direction,low density,low viscosity,low solidification point,low sulfur content,production characteristics show that the initial weekly output comprehensive decline rate of 11%,oil well moisture content changes greatly,the use of volume method for reserve estimation,estimation of petroleum geological reserves 630.96×10~4t,overlapping oil-containing area of 17.822km~2,reserve abundance of 35.4×104t/km~2.