Pressure Data Analysis and Reservoir Parameter Estimation of Kailastilla Gas Field (Well No. KTL-01 and KTL-02)

Abstract

Well testing has been the subject of research for many decades. Well tests are performed in order to estimate reservoir properties. These estimations are needed to predict the amount of oil or gas that can be produced, and to determine a strategy how to produce this predicted amount. The current method to estimate the reservoir properties seems cumbersome and inefficient. Also, uncertainty regions of the estimated properties are not yet available. The reservoir parameter estimation on the basis of pressure transient data and production data at the well is an essential part in the prediction of reservoir behavior. The estimation of these parameters in a dynamic system is referred to as parameter estimation, identification or inverse problem. In this paper, the reservoir parameters – permeability, skin factor, average pressure, wellbore storage coefficient, reservoir drainage extent – are estimated on the basis of pressure data observed at the wellbore and production data using buildup test (MBH) and deliverability test methods. This paper represents the contribution in quantifying the effects of wellbore storage along with the skin intensity on deliverability from gas wells. Generalized charts for type curve studies on gas wells, based on pseudo-pressure and pressure-squared concepts, along with wellbore storage, are presented with applications and support from field data.

Keywords: Flow-after-flow test, buildup test, type curve analysis, pressure transient test, skin factor, wellbore storage, inflow performance curve