元坝地区须三气藏储集层以中粗粒钙屑砂岩、粉细砂岩为主,孔隙度平均值1.82%~2.61%,渗透率平均值0.016~0.029 m D,属低孔低渗致密砂岩储层,储集层裂缝较发育,且裂缝对改善储集层的孔隙度和渗透率影响较大。本文运用常规测井资料通过岩...元坝地区须三气藏储集层以中粗粒钙屑砂岩、粉细砂岩为主,孔隙度平均值1.82%~2.61%,渗透率平均值0.016~0.029 m D,属低孔低渗致密砂岩储层,储集层裂缝较发育,且裂缝对改善储集层的孔隙度和渗透率影响较大。本文运用常规测井资料通过岩心标定裂缝的测井响应特征,利用砂岩裂缝交会分析方法,优选声波时差、密度两个参数建立的判别方程,通过逐步判别识别原理及概率计算,对单井进行裂缝识别,并进行裂缝孔隙度和宽度的计算,绘制单井裂缝参数解释剖面,评价单井裂缝发育情况,建立该储集层裂缝识别的综合标准。展开更多
Based on the GC-MS analytical data of aromatic fractions of over forty highly mature coal-bearing source rock samples collected from the Upper Triassic Xujiahe Formation in the northern Sichuan Basin, the thermal evol...Based on the GC-MS analytical data of aromatic fractions of over forty highly mature coal-bearing source rock samples collected from the Upper Triassic Xujiahe Formation in the northern Sichuan Basin, the thermal evolution of aromatic hydrocarbons during late-mature to over-mature stage （R0=1.13%-2.85%） was characterized, and aromatic indicators suitable for recognizing the organic source and sedimentary environment of high maturity source rocks were discussed. The results indicated that the concentrations of low carbon-cycle naphthalene as well phenanthrene series reduce gradually with increasing Ro at the highly mature levels. However, some high-cyclic components such as chrysene, benzofluoranthene, and benzo[e]pyrene are relatively enriched, in companying an enhancement of parent aromatic compounds. The variations are attributed to thermal cracking and polymerization reactions due to continuous dehydrogenation under enhanced burial temperature. As thermal maturity rises, MPI1 （Methylphenanthrene Index） values display a two-modal varying trend, namely, increasing when Ro is below 1.80% and decreasing above 1.8% Ro. The relationships between Ro and MPI1 are Ro=0.98MPI1＋0.37 for R0〈1.80% and R0=-0.90MPI1＋3.02 at R0〉1.8%, being different from the previous research. The amount of dibenzofurans declines sharply at Ro higher than 1.1%, leading to a significant change of relative composition among dibenzothiophenes, dibenzofurans and fluorenes （referred as three-fluorenes series composition）. Thus, this parameter appears to be unsuitable for identifying the sedimentary environment of the highly matured source rocks. 4-/1-MDBT （methyldibenzothiophene） ratio could be served as an effective indicator for organic facies, and can distinguish coals from mudstones at over-maturity in this case. The ratios of 2,6-/2,10-DMP （dimethylphenanthrene） and 1,7-/1,9-DMP and relative abundance of triaromatic steroids in these highly mature rocks could be considered as biological source parameters for relative input of terrigenous versus aquatic organic matter.展开更多
文摘元坝地区须三气藏储集层以中粗粒钙屑砂岩、粉细砂岩为主,孔隙度平均值1.82%~2.61%,渗透率平均值0.016~0.029 m D,属低孔低渗致密砂岩储层,储集层裂缝较发育,且裂缝对改善储集层的孔隙度和渗透率影响较大。本文运用常规测井资料通过岩心标定裂缝的测井响应特征,利用砂岩裂缝交会分析方法,优选声波时差、密度两个参数建立的判别方程,通过逐步判别识别原理及概率计算,对单井进行裂缝识别,并进行裂缝孔隙度和宽度的计算,绘制单井裂缝参数解释剖面,评价单井裂缝发育情况,建立该储集层裂缝识别的综合标准。
基金supported by the Key State Science and Technology Project(Grant No.2011ZX05005-03-009HZ)the Specialized Research Fund for the Doctoral Program of Higher Education(Grant No.20130101110051)
文摘Based on the GC-MS analytical data of aromatic fractions of over forty highly mature coal-bearing source rock samples collected from the Upper Triassic Xujiahe Formation in the northern Sichuan Basin, the thermal evolution of aromatic hydrocarbons during late-mature to over-mature stage （R0=1.13%-2.85%） was characterized, and aromatic indicators suitable for recognizing the organic source and sedimentary environment of high maturity source rocks were discussed. The results indicated that the concentrations of low carbon-cycle naphthalene as well phenanthrene series reduce gradually with increasing Ro at the highly mature levels. However, some high-cyclic components such as chrysene, benzofluoranthene, and benzo[e]pyrene are relatively enriched, in companying an enhancement of parent aromatic compounds. The variations are attributed to thermal cracking and polymerization reactions due to continuous dehydrogenation under enhanced burial temperature. As thermal maturity rises, MPI1 （Methylphenanthrene Index） values display a two-modal varying trend, namely, increasing when Ro is below 1.80% and decreasing above 1.8% Ro. The relationships between Ro and MPI1 are Ro=0.98MPI1＋0.37 for R0〈1.80% and R0=-0.90MPI1＋3.02 at R0〉1.8%, being different from the previous research. The amount of dibenzofurans declines sharply at Ro higher than 1.1%, leading to a significant change of relative composition among dibenzothiophenes, dibenzofurans and fluorenes （referred as three-fluorenes series composition）. Thus, this parameter appears to be unsuitable for identifying the sedimentary environment of the highly matured source rocks. 4-/1-MDBT （methyldibenzothiophene） ratio could be served as an effective indicator for organic facies, and can distinguish coals from mudstones at over-maturity in this case. The ratios of 2,6-/2,10-DMP （dimethylphenanthrene） and 1,7-/1,9-DMP and relative abundance of triaromatic steroids in these highly mature rocks could be considered as biological source parameters for relative input of terrigenous versus aquatic organic matter.
