Genetic types and distinguished characteristics of dolomite and the origin of dolomite reservoirs

Wenzhi ZHAO,Anjiang SHEN,Zhanfeng QIAO,Liyin PAN,Anping HU,Jie ZHANG

Fig. 6. Types and origins of dolomite reservoir space. (a) Electron back-scattering microscopic image shows dolomitized sponge spicule, tissue and spongin, Changxing Formation, Well Longgang 001, Sichuan Basin; (b) Distribution analysis image of Mg with the same view field with (a), dark parts in electron back-scattering microscopic image are dolomite; (c) Local enlarged electron back-scattering microscopic image of view field of (a) shows micro pores (P) micro-pores generated by dolomitization (D) are mainly in dolomite, with few in calcite (L); (d) Oomold pores in fine crystalline dolomite with primary grain texture, Feixianguan Formation, Well Luojia 2, Sichuan Basin; (e) Non-fabric selective pores generated by burial-hydrothermal dissolution, powder to fine crystalline dolomite, Middle to Lower Cambrian, Well Yaha 10, Tarim Basin; (f) Moldic pores of crystal dolomite, fine crystalline dolomite, Longwangmiao Formation, Well Moxi21, Sichuan Basin.