岩石力学与工程学报
巖石力學與工程學報
암석역학여공정학보
CHINESE JOURNAL OF ROCK MECHANICS AND ENGINEERING
2013年
z2期
3116-3122
,共7页
岩石力学%孔隙特征%喉道分布%有效孔喉体积%恒速压汞%特低渗透砂岩%鄂尔多斯盆地
巖石力學%孔隙特徵%喉道分佈%有效孔喉體積%恆速壓汞%特低滲透砂巖%鄂爾多斯盆地
암석역학%공극특정%후도분포%유효공후체적%항속압홍%특저삼투사암%악이다사분지
rock mechanics%pore characteristics%throat distribution%effective pore throat volume%constant rate mercury penetration%extra-low permeability sandstone%Ordos basin
为从微观角度认识特低渗透砂岩的微观孔喉特征,明确制约储层品质和开发效果的关键因素,利用恒速压汞技术对鄂尔多斯盆地延长组的样品进行测试,定量表征孔喉特征参数。结果表明:特低渗透砂岩孔隙之间的差异很小,孔隙半径基本分布于70~225μm范围内,峰值在110μm左右;渗透率小时,喉道分布集中,小喉道含量高,喉道对渗透率的贡献也集中分布,贡献峰值大;喉道半径的分布范围随着渗透率的增大而变宽,大喉道含量及其对渗透率的贡献也随之增大。平均喉道半径与渗透率的相关性较好,渗透率小于1.0×10-3μm2时,平均喉道半径的波动幅度大,特低渗透砂岩敏感的根源在于特殊的喉道特征,物性(尤其是渗透率)差的根本原因在于细小喉道所占比例较大。物性(尤其是渗透率)越好,有效孔隙、喉道越发育。微观孔喉特征的差异主要体现在喉道的大小及其分布上,喉道决定储层品质,影响开发效果。
為從微觀角度認識特低滲透砂巖的微觀孔喉特徵,明確製約儲層品質和開髮效果的關鍵因素,利用恆速壓汞技術對鄂爾多斯盆地延長組的樣品進行測試,定量錶徵孔喉特徵參數。結果錶明:特低滲透砂巖孔隙之間的差異很小,孔隙半徑基本分佈于70~225μm範圍內,峰值在110μm左右;滲透率小時,喉道分佈集中,小喉道含量高,喉道對滲透率的貢獻也集中分佈,貢獻峰值大;喉道半徑的分佈範圍隨著滲透率的增大而變寬,大喉道含量及其對滲透率的貢獻也隨之增大。平均喉道半徑與滲透率的相關性較好,滲透率小于1.0×10-3μm2時,平均喉道半徑的波動幅度大,特低滲透砂巖敏感的根源在于特殊的喉道特徵,物性(尤其是滲透率)差的根本原因在于細小喉道所佔比例較大。物性(尤其是滲透率)越好,有效孔隙、喉道越髮育。微觀孔喉特徵的差異主要體現在喉道的大小及其分佈上,喉道決定儲層品質,影響開髮效果。
위종미관각도인식특저삼투사암적미관공후특정,명학제약저층품질화개발효과적관건인소,이용항속압홍기술대악이다사분지연장조적양품진행측시,정량표정공후특정삼수。결과표명:특저삼투사암공극지간적차이흔소,공극반경기본분포우70~225μm범위내,봉치재110μm좌우;삼투솔소시,후도분포집중,소후도함량고,후도대삼투솔적공헌야집중분포,공헌봉치대;후도반경적분포범위수착삼투솔적증대이변관,대후도함량급기대삼투솔적공헌야수지증대。평균후도반경여삼투솔적상관성교호,삼투솔소우1.0×10-3μm2시,평균후도반경적파동폭도대,특저삼투사암민감적근원재우특수적후도특정,물성(우기시삼투솔)차적근본원인재우세소후도소점비례교대。물성(우기시삼투솔)월호,유효공극、후도월발육。미관공후특정적차이주요체현재후도적대소급기분포상,후도결정저층품질,영향개발효과。
The samples of Yanchang group in Ordos basin are tested with constant rate mercury penetration technique , pore throat characteristics parameters are characterized quantitatively in order to recognize the micro-pore throat characteristics and to make definite the key factors controlling reservoir quality and development effect. The results show that difference of pore is little,pore radius distributes in 70-225μm,peak value is about 110μm. When the permeability is low,the throat distributes assembly,the content of small throat is high,the contribution of throat to permeability also distributes intensively and contribution of peak value is big. Distribution range of throat radius will become wide,large pore content will increase and its contribution will broaden with the increasing permeability. Average pore radius and permeability present good correlation. Fluctuation amplitude of average pore radius is great when the permeability is less than 1.0×10-3μm2. Sensibility of extra-low permeability sandstone roots in particular throat characteristics. The poor physical properties(especially permeability) lie in the high content of small throat. The well the physical property is,the more the effective pore and throat develop. Difference of micro-pore throat mainly is presented in the pore size and its distribution. The pore controls the reservoir quality and affects development effect.