Int. J. of Oil, Gas and Coal Technology   »   2017 Vol.14, No.4



Title: Gas/condensate production decline analysis using type curves


Authors: Mohammad Taghizadeh Sarvestani; Fariborz Rashidi; Sayed Ali Mousavi Dehghani


Department of Petroleum Engineering, Amirkabir University of Technology, Tehran, Iran
Department of Chemical Engineering, Amirkabir University of Technology, 424 Hafez Ave, 15875-4413, Tehran, Iran
Research Institute of Petroleum Industry, National Iranian Oil Company, R.I.P.I., Tehran, Iran


Abstract: Abnormal thermodynamic behaviour and multi-phase flow of gas/condensate reservoirs restrict the application of available production models to analyse production data in order to estimate reservoir properties. This study aims at development of a new analytical model to estimate initial gas-in-place, average reservoir pressure, drainage area size, permeability, and well skin from multi-phase gas/condensate production data via type curves. For this purpose, the governing flow equation of multi-phase gas/condensate reservoir is derived and by employing novel two-phase pseudo-functions, a general boundary dominated flow solution is developed for variable bottom-hole pressure/rate conditions. The effects of positive coupling and negative inertia in the near-wellbore region are also included in the formulation. Subsequently, the obtained production model is presented in type curve analysis format by using new dimensionless parameters. The proposed model is validated using different synthetic compositional models by changing different reservoir and fluid properties including reservoir fluid types, relative permeability data, and production history mode. In addition, the method is evaluated using actual field data. Results show that the proposed method estimates the reservoir properties quite well for all cases. [Received: December 1, 2014; Accepted: October 6, 2015]


Keywords: two-phase pseudo-function; gas/condensate reservoirs; type curves; initial gas-in-place; boundary dominated flow; production data; analytical modelling; average reservoir pressure; drainage area size; permeability; well skin; reservoir properties; thermodynamics; multi-phase flow; bottom-hole pressure; near-wellbore region.


DOI: 10.1504/IJOGCT.2017.10003993


Int. J. of Oil, Gas and Coal Technology, 2017 Vol.14, No.4, pp.303 - 338


Available online: 20 Mar 2017



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