The Volcanic Reservoir Porosity Types And Causes Of Kelameili Dixi 17 Well Area

The Dixi area locates in the mid-west of dinan hill,which in the eastern Luliang Uplift of the Junggar Basin drops. Many high gas rate wells have been found in the Carboniferous volcanic rocks, and the Dixi 17-well area is one of them. According to core observation, thin section and the casting thin sections observation and polarized microscope identified, rock chemical and physical data analysis; the Dixi 17 wells Carboniferous volcanic rocks characteristics, pore types and causes of research showed that:1. The Dixi 17 wells of the Carboniferous rocks are main of volcanic lava and pyroclastic rocks and volcanic- sedimentary clastic rocks. The lava are main of basalt, andesite and basaltic andesite; pyroclastic rocks, mainly tuff breccia, sintering volcanic breccias; the volcanic- sedimentary are mainly clastic tuff.2. The Dixi 17 wells of the Carboniferous volcanic porosity type are pores and fissures, each divided into primary and secondary two subcategories, 17-well area of development of stomata, almond body residual hole, intergranular pores, dissolution fracture etc 14 categories reservoir space. The main reservoir rocks are stomata basalt, almond-shaped basalt, tectonic breccia, different types of different rock types of pore.3. The primary pore causes Dixi 17 wells : the volcanic conduit facies form a mesh, radial, ring cracks, gravel fracture; the primary porosity of the outbreak facies of the volcanic clastic rocks and volcanic sedimentary rock class causes and clastic sedimentary rocks are the similar causes, the formation of intergranular pores for the accumulation of clastic particles, holes between the boulders; overflow and the outbreak of lava formation of pores and condensation contraction joints.4. The Dixi 17 wells of secondary porosity by the dissolution(solution) the role of weathering and leaching and tectonic formation. Dissolution mainly produce various types of corrosion aperture; weathering and leaching is not only the formation of broken crack still in groundwater of the role of the formation of various corroded fissure; the tectonic also produce fractures, and the tectonic fractures provide the late hydrothermal flow channel, and formed dissolution pore.