Article

Petroleum Geology & Experiment

, 37:4

First online:

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Development characteristics and hydrocarbon accumulation significance of fractures in Lower Silurian Kalpintag Formation, northern slope of central Tarim Basin

  • Guo HuiAffiliated withResearch Institute of Petroleum Exploration & Production, SINOPEC Northwest Company Email author 
  • , Ma ZhongyuanAffiliated withResearch Institute of Petroleum Exploration & Production, SINOPEC Northwest Company
  • , Zhang LiAffiliated withResearch Institute of Petroleum Exploration & Production, SINOPEC Northwest Company
  • , Huang WeiAffiliated withResearch Institute of Petroleum Exploration & Production, SINOPEC Northwest Company
  • , Yang SujuAffiliated withResearch Institute of Petroleum Exploration & Production, SINOPEC Northwest Company

Abstract

Based on the data of core, microscope thin section, scanning electron microscope, cathode luminescence, and conventional and dipole acoustic logging, the development characteristics and hydrocarbon accumulation significance of fractures in the Lower Silurian Kalpintag Formation on the northern slope of the central Tarim Basin were studied. A large number of mainly high-angle or vertical fractures developed in the study area. They feature low density, long length, medium width and low filling extent. More fractures were found in the relatively weak bands of rock, such as the margins and interlayers of boulder clays. Conventional logging curves showed two peaks and one order of magnitude difference. The anisotropy of fast shear wave in dipole acoustic logging showed that fracture development was influenced by NE trending strike-slip faults and the NE-SW trending maximum horizontal principal stress. The fractures in the Kalpintag Formation played important roles in the formation of tight sand-stone reservoirs. They improved the porosity and permeability of tight sandstones, and the large-scale, high-angle or vertical fractures served as pathways for vertical migration of hydrocarbons. For the small-scale adjustment of hydrocarbon migration, the small-scale, low-angle or horizontal fractures were important.

Key words:

fracture accumulation significance Kalpintag Formation Lower Silurian northern slope of central Tarim Basin

塔中北坡下志留统柯坪塔格组裂缝发育特征及成藏意义