Investigation of Capillary Pressure Effects on Wireline Formation Testing and Free-water Level Estimation

Abstract

Formation Evaluation is the process of interpreting a combination of measurements taken inside a wellbore to detect and quantify oil and gas reserves in the rock adjacent to the well. One of the data sources from which valuable data can be obtained is the wireline formation testing. In this study, the wireline formation testing and special core analysis data were integrated. The data study were laboratory capillary pressure data from three samples of J-2-Well; one was measured using mercury injection methods and the other two by porous diagram method. Wireline formation testing data from one well J-1 have been quality-checked and analyzed to obtain fluids pressure gradients. The objective of the study is to investigate the effect of capillary pressure on wireline formation testing measurements. This has been performed through the estimation of the free water level using two different methods, i.e., from pressure gradients and from capillary pressure data. It has been found that the free water level obtained from WFT data and from capillary pressure data was at 1,553m, 1,550 m respectively. The difference between the two values shows the quantitative effect of capillary pressure on wire line formation testing measurements. This result will be important for the interpretation and the analysis which lead to the estimation of the free-water level in addition to taking into consideration all further analyses and calculations which are based on it.