Logging Evaluation Of Low-grade Formation Potential Of Sha3 3 In Dagang X Fault Block

Sha3 of fault block X in Wangguantun oilfield is a non-main development layer.Logges explain that a large number of thin and dry layers are collectively called low quality layers.Some of the low quality development processes have good oil production effect,so it is necessary to reevaluate the oil potential of these low quality layers.There are many old Wells in the study area,the logging period is longer,and the data of coring Wells are less.It is very difficult to identify oil and water because the development of non-main strata adopts the way of combining layers and putting into production.In view of the above situation,this paper identified the lithologic characteristics of the reservoir through core combined with logging data,studied the physical properties of the Sha-3 reservoir by using core analysis data,analyzed the pore structure of the low porosity and permeability reservoir by mercury injection test,CT scan and thin section,and obtained the following understandings: The reservoirs are mainly fine sandstone and medium sandstone,and the lithology identification standard of natural gamma-resistivity reservoir is established.The physical characteristics are middle and low porosity and middle and low permeability reservoirs.The low porosity and permeability reservoirs are mainly small and micro pore throats with poor connectivity.The formation reasons of low porosity and permeability reservoirs are analyzed.It is of great potential to identify the logging characteristics of oil reservoir,water reservoir and dry reservoir previously explained,and to analyze the low grade formation of Sha-3 by histogram of acoustic time difference and frequency distribution of resistivity.Then,three types of potential identification charts of acoustic time difference and resistivity were established by Wells with good production results.By using the method of cross identification,12 potential Wells were screened and 31 potential layers were obtained.At the same time,the potential layers were comprehensively analyzed according to the development characteristics and production conditions of adjacent Wells.Crossplot technique and experience formula method is used for three 3 reservoir sand shale content,porosity and permeability parameters calculating,using rock electricity experiment to calculate electric parameter reconstruction saturation model,then using the established fine secondary logging interpretation model explains the whole 43 Wells,explain the layer number of up to 256 layers,explain the thickness of a total of 621.1 m.Six potential Wells were selected for oil test,two of which were adopted by the oil field.The production of 3.2t per day for the potential well G8-13-2was good,and the remaining potential Wells were considered for production when the subsequent conditions were suitable.