›› 2018, Vol. 39 ›› Issue (5): 1-1.doi: 10.7657/XJPG20180515

   

Well Test Interpretation Model for Deviated Wells in Tri-Porosity-Media and Homogeneous Composite Carbonate Gas Reservoirs

MENG Fankun1, LEI Qun1, HE Dongbo1, YAN Haijun1, DENG Hui2, XU Wei2   

  1. (1.Research Institute of Petroleum Exploration & Development, PetroChina, Beijing 100083, China; 2.Research Institute of Exploration and Development, Southwest Oil and Gas Field Company, PetroChina, Chengdu, Sichuan 610051, China)
  • Online:2019-01-01 Published:1905-07-18

Abstract: In the deviated wells drilled in the carbonate gas reservoirs in Gaoshiti—Moxi area, because fractures and karst caves are developed in the near wellbore areas and matrix is extensively distributed in the areas far from wellbore, the paper comprehensively uses the methods of Laplace transformation, Fourier transformation and inverse transformation, and point-source function combination, takes the influences of wellbore storage coefficient and skin factor into consideration, establishes a well test model for deviated wells in tri-porosity-media and homogeneous composite gas reservoirs and uses Stehfest numerical inversion method to obtain the solution of the model. Compared with the solution obtained from a well test model for vertical wells in tri-porosity-media and homogeneous composite gas reservoirs, the validity of the established model is verified. Based on the classified flowing phases, the influences of wellbore storage coefficient, skin factor, interporosity flow coefficient, inner zone radius and hole deviation angle on well test curves are analyzed. A typical well test curve can be divided into 7 phases, the increase of wellbore storage coefficient will cover up the influence of well deviation on the curve, interporosity flow coefficient will bring impact to the appearance of channeling phase and the inner zone radius can determine the time of pressure arriving at the interface between the inner and out zones. When the hole deviation angle is lower than 50°, skin factor will decrease with the increase of the deviation angle and the well test curves will have the same characteristics; when the hole deviation angle is higher than 50°, obvious radial flow in the vertical direction will occur.

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