. . SPE 26933 A Simple Method for Evaluating Pore Surface Mineralogy Shahab Mohaghegh, Samuel Ameri, and Khashayar Aminian, West Virginia U. SPE Members -~1 1*, 50GW of Petroleum Engineers, inc. l’hle pspar wee preparaf for praaanlation ~t the 1SS3 Eastern Ragiond Conference 6 Exhibilti fwfd in Pmsburgh, PA, U. S.A., 2-4 Novembar 19S3. socbtY of PetrotsufnEnuinssr8 I We paper waa safactW for praaantafkm by an SPE Prcqram Commfftaa Mowing whew of intormafff contained in an abatracf submitted by the author(s). C4ntents of tfw paper, os ECOOSOtad,havo not ban ravkwed by the Society d Pafrc4aum Enoinaars and are aubjact 10 correction by the avthor(s), The material, w preaantad, does not nacaaaarify reflect any podtfon d the Society of %trdaum En@aara, Ha offkara, or mambera. Papere praaantad at SPE meetinge are aubjact to pubfkatbn rwfaw by Edkorfal Committees of the Society d~E~. ~~mqb~@man ti@d~wet~~~.l~ may nc4ba CO@WI. The absfmof afvaufd contain conapicuowacknowlad!mant of where arnf by wiwrr the papa b prasantad. Write LWarian, SPE, P.O. SOX -, Rkhafd-t ~ 7~, U. S.A., TOkX 1S3245 SPEUT. ABSTRACT Majority of mineralogical studies directed at hydrocarbon producing formations are conventional studies that treat the formation as a bulk entity. Focusing on pore surface mineralogy, which is the identification of the elemental composition of the pore surface, seems to be a more realistic approach, since fluids in the formation come into direct contact with these elements on the surface. Rock-fluid properties such as relative permeability, nettability, capilla~ pressure and certain rock properties, are influenced by pore surface mineralogy. Hence, characterization of pore surface mineralogy will enhance understanding of the interaction between fluid and the porous medium. This paper discusses Multiple Voltage Scanning Electron Microscopy as a novel method for characterization of pore surface mineralogy. Multiple Voltage Scanning Electron Microscopy, a new method that has references and illustrations at the end o- / 395 successfully been used to study the surface of particles, has been implemented to identify the elemental composition of pore surface. Results of the investigations of pore sufface mineralogy for a resewoir in West Virginia is presented. This reservoir has experienced high injection pressures during a watetiooding project. The concentration of clays on the pore surface can be a possible explanation for high injection pressure. This paper will t~ to direct the attention of scientists and researchers to this issue and emphasize ?he importance of pore surface mineralogy and its effects on rock-fluid properties. INTRODUCTION Identification of the mineralogical makeup of the hydrocarbon producing rocks is an old and common practice during the resefvoir characterization process. Thin section analysis, in which a ve~ thin slice of the rock is cut and