Shale acoustic logging response law is complex due to the multiple minerals and pores,which limits the application of acoustic logging in shale reservoir parameter evaluation,therefore clarifying the shale acoustic lo...Shale acoustic logging response law is complex due to the multiple minerals and pores,which limits the application of acoustic logging in shale reservoir parameter evaluation,therefore clarifying the shale acoustic logging response law is of great importance.Different petrophysical models are adopted for the equivalence of organic matter,clay,matrix minerals,and fractures,in Wufeng-Longmaxi shale formation in the Jiaoshiba area.Finally,the self-consistent approximation model is used to combine different components,and a shale petrophysical model with a complex pore structure is constructed.The model verification results show it has good predictability for shale.Based on the model,the effect of different mineral compositions and different types of pores are studied.The results show that:1)The effect of clay and organic matter is very complex,and the variation laws of layered clay(organic matter)and dispersed clay(organic matter)on the acoustic wave are consistent.2)Layered clay or organic matter leads to the formation anisotropy increase,which makes the acoustic time difference greater than that of containing dispersed clay(organic matter).3)The fracture is the main control factor of anisotropy,and the anisotropy of gas-bearing fracture is higher than that of water/oil fracture.展开更多
Based on the analysis of the responses of conventional logs such as natural gamma(GR), density(DEN), acoustic interval transit time(AC), compensated neutron(CNL), dual lateral resistivity(Rlld, Rlls), and caliper log(...Based on the analysis of the responses of conventional logs such as natural gamma(GR), density(DEN), acoustic interval transit time(AC), compensated neutron(CNL), dual lateral resistivity(Rlld, Rlls), and caliper log(CAL), combined with drilling data,cores, thin section and productivity of 65 wells, the reservoirs in the Mid-Permian Maokou Formation of southern Sichuan Basin were divided into four types, fractured-vuggy, pore-vuggy, fractured and fractured-cavity. The main reservoirs in high productivity wells are fractured-vuggy and pore-vuggy. The reservoirs of Maokou Formation are generally thin, and can be divided into the upper reservoir segment(layer a of the second member to the third member of Maokou Formation, P_2 m^2 a-P_2 m^3) and the lower segment(layer b of the second member of Maokou Formation, P_2 m^2 b). The two reservoir segments are mainly controlled by two grain beaches during the sedimentation of P_2 m^2 a-P_2 m^3 and P_2 m^2 b, the vertical zonation of karst, and the fractures. The upper reservoir segment is generally better than the lower one in development degree and single well productivity, and is much thicker than the lower one. It is thicker in the Yibin-Zigong-Weiyuan-Dazu area, the southwestern area of Chongqing and the southeastern area of Luzhou, while the lower segment is thicker in the Neijiang-Zigong-Luzhou area and the Dazu-Luzhou area. The areas with big reservoir thickness at tectonic slope or syncline parts are the favorable exploration areas.展开更多
泥页岩地层通常具有低孔、低渗特征,存在裂缝及裂缝发育程度均是其能够成为储层的决定性条件。以苏北盆地阜宁组泥页岩地层为研究对象,研究裂缝特征及其与岩性、物性、含油性、电性及可压裂性("五性")之间的关系。结果表明:...泥页岩地层通常具有低孔、低渗特征,存在裂缝及裂缝发育程度均是其能够成为储层的决定性条件。以苏北盆地阜宁组泥页岩地层为研究对象,研究裂缝特征及其与岩性、物性、含油性、电性及可压裂性("五性")之间的关系。结果表明:裂缝普遍含油,发育裂隙的样品渗透率明显较高,一般都大于10 m D,裂缝对改善泥页岩地层的渗透性及储集性起到了重要作用;含裂隙样品通常脆性矿物(方解石)含量较高,对应的岩性一般为灰质泥岩、含灰页岩及含灰泥岩;天然裂隙发育的层段杨氏模量较高、泊松比较低、脆性系数较高,页岩的脆性较强,通常易于压裂改造。利用测井响应特征可明显区分方解石充填裂缝和有油迹显示的无充填裂缝,可为识别有效泥页岩储层提供依据。展开更多
基金financially supported by the National Natural Science Foundation of China(NSFC)Basic Research Program on Deep Petroleum Resource Accumulation and Key Engineering Technologies(Grant No.U19B6003-04-03-03)The Key Project of Sinopec Ministry of Science and Technology(Grant No.PE19012-1)the National Research Council of Science and Technology Major Project(Grant No.2016ZX05060-001-012)。
文摘Shale acoustic logging response law is complex due to the multiple minerals and pores,which limits the application of acoustic logging in shale reservoir parameter evaluation,therefore clarifying the shale acoustic logging response law is of great importance.Different petrophysical models are adopted for the equivalence of organic matter,clay,matrix minerals,and fractures,in Wufeng-Longmaxi shale formation in the Jiaoshiba area.Finally,the self-consistent approximation model is used to combine different components,and a shale petrophysical model with a complex pore structure is constructed.The model verification results show it has good predictability for shale.Based on the model,the effect of different mineral compositions and different types of pores are studied.The results show that:1)The effect of clay and organic matter is very complex,and the variation laws of layered clay(organic matter)and dispersed clay(organic matter)on the acoustic wave are consistent.2)Layered clay or organic matter leads to the formation anisotropy increase,which makes the acoustic time difference greater than that of containing dispersed clay(organic matter).3)The fracture is the main control factor of anisotropy,and the anisotropy of gas-bearing fracture is higher than that of water/oil fracture.
基金Supported by the PetroChina Science and Technology Project(KT2018-01-02)
文摘Based on the analysis of the responses of conventional logs such as natural gamma(GR), density(DEN), acoustic interval transit time(AC), compensated neutron(CNL), dual lateral resistivity(Rlld, Rlls), and caliper log(CAL), combined with drilling data,cores, thin section and productivity of 65 wells, the reservoirs in the Mid-Permian Maokou Formation of southern Sichuan Basin were divided into four types, fractured-vuggy, pore-vuggy, fractured and fractured-cavity. The main reservoirs in high productivity wells are fractured-vuggy and pore-vuggy. The reservoirs of Maokou Formation are generally thin, and can be divided into the upper reservoir segment(layer a of the second member to the third member of Maokou Formation, P_2 m^2 a-P_2 m^3) and the lower segment(layer b of the second member of Maokou Formation, P_2 m^2 b). The two reservoir segments are mainly controlled by two grain beaches during the sedimentation of P_2 m^2 a-P_2 m^3 and P_2 m^2 b, the vertical zonation of karst, and the fractures. The upper reservoir segment is generally better than the lower one in development degree and single well productivity, and is much thicker than the lower one. It is thicker in the Yibin-Zigong-Weiyuan-Dazu area, the southwestern area of Chongqing and the southeastern area of Luzhou, while the lower segment is thicker in the Neijiang-Zigong-Luzhou area and the Dazu-Luzhou area. The areas with big reservoir thickness at tectonic slope or syncline parts are the favorable exploration areas.
文摘泥页岩地层通常具有低孔、低渗特征,存在裂缝及裂缝发育程度均是其能够成为储层的决定性条件。以苏北盆地阜宁组泥页岩地层为研究对象,研究裂缝特征及其与岩性、物性、含油性、电性及可压裂性("五性")之间的关系。结果表明:裂缝普遍含油,发育裂隙的样品渗透率明显较高,一般都大于10 m D,裂缝对改善泥页岩地层的渗透性及储集性起到了重要作用;含裂隙样品通常脆性矿物(方解石)含量较高,对应的岩性一般为灰质泥岩、含灰页岩及含灰泥岩;天然裂隙发育的层段杨氏模量较高、泊松比较低、脆性系数较高,页岩的脆性较强,通常易于压裂改造。利用测井响应特征可明显区分方解石充填裂缝和有油迹显示的无充填裂缝,可为识别有效泥页岩储层提供依据。
