石油实验地质
石油實驗地質
석유실험지질
EXPERIMENTAL PETROLEUM GEOLOGY
2013年
4期
401-406,413
,共7页
孔隙喉道类型%孔喉差异%特低渗透砂岩%延长组%西山窑组%吴起地区%牛圈湖地区
孔隙喉道類型%孔喉差異%特低滲透砂巖%延長組%西山窯組%吳起地區%牛圈湖地區
공극후도류형%공후차이%특저삼투사암%연장조%서산요조%오기지구%우권호지구
pore throat type%differences of pore throat%extra-low permeability sandstone%Yanchang Forma-tion%Xishanyao Formation%Wuqi area%Niujuanhu area
因沉积和成岩作用改造不同，渗透率相近或相等的砂岩，微观孔喉特征参数存在明显差异。以吴起地区延长组长6砂岩和牛圈湖地区西山窑组X2砂岩为对象，综合利用物性、铸体薄片和恒速压汞对不同孔喉匹配关系下的微观孔喉特征参数进行了定量对比。结果表明，各渗透率级别样品的孔隙参数差异不大，微观孔喉特征的差异主要体现在喉道上。发育的溶蚀孔和晶间孔造成X2砂岩的弯片状、管束状喉道含量高，喉道半径小且分布范围窄，对渗透率贡献集中，平均喉道半径和主流喉道半径小、大孔喉比含量高。长6砂岩缩颈状、片状和弯片状喉道发育，喉道半径差异大、大喉道含量高的特征归因于发育的原生粒间孔。不同孔喉匹配关系下的特低渗透砂岩，开发过程中应区别对待。
因沉積和成巖作用改造不同，滲透率相近或相等的砂巖，微觀孔喉特徵參數存在明顯差異。以吳起地區延長組長6砂巖和牛圈湖地區西山窯組X2砂巖為對象，綜閤利用物性、鑄體薄片和恆速壓汞對不同孔喉匹配關繫下的微觀孔喉特徵參數進行瞭定量對比。結果錶明，各滲透率級彆樣品的孔隙參數差異不大，微觀孔喉特徵的差異主要體現在喉道上。髮育的溶蝕孔和晶間孔造成X2砂巖的彎片狀、管束狀喉道含量高，喉道半徑小且分佈範圍窄，對滲透率貢獻集中，平均喉道半徑和主流喉道半徑小、大孔喉比含量高。長6砂巖縮頸狀、片狀和彎片狀喉道髮育，喉道半徑差異大、大喉道含量高的特徵歸因于髮育的原生粒間孔。不同孔喉匹配關繫下的特低滲透砂巖，開髮過程中應區彆對待。
인침적화성암작용개조불동，삼투솔상근혹상등적사암，미관공후특정삼수존재명현차이。이오기지구연장조장6사암화우권호지구서산요조X2사암위대상，종합이용물성、주체박편화항속압홍대불동공후필배관계하적미관공후특정삼수진행료정량대비。결과표명，각삼투솔급별양품적공극삼수차이불대，미관공후특정적차이주요체현재후도상。발육적용식공화정간공조성X2사암적만편상、관속상후도함량고，후도반경소차분포범위착，대삼투솔공헌집중，평균후도반경화주류후도반경소、대공후비함량고。장6사암축경상、편상화만편상후도발육，후도반경차이대、대후도함량고적특정귀인우발육적원생립간공。불동공후필배관계하적특저삼투사암，개발과정중응구별대대。
There are different pore throat matching relationship and micro-pore throat characteristics for similar or equal sandstones because of different deposition and diagenesis reconstruction. Taking the Chang6 sandstone of Yanchang Formation in Wuqi area and the X2 sandstone of Xishanyao Formation in Niujuanhu area as the objects, the micro-pore throat characteristics in different pore throat matching relationships are evaluated quantitatively using physical property testing, cast section and constant rate mercury penetration technique. The results show that there are no obvious differences in pore parameters, and the differences of micro-pore throat characteristics are mainly presented in throat parameters for samples with different permeabilities. As to the X2 sandstone, the generation of dissolution pores and intercrystal pores leads to high content of curved lamellar and tube bundle throat, small throat radius and narrow distribution, concentrated contribution of throat to permeability, fine aver-age throat radius and main flow throat radius, high content of big pore throat ratio in Niujuanhu area. In the Chang6 sandstone, necking, flaky and curved lamellar throats develop, throat radius vary obviously, and big throats are in high content, which can be explained by the generation of primary intercrystal pores. Different steps should be taken in the development process for extra-low permeability sandstone reservoirs which present different pore throat matching relationships.
