Scoring System as a Quick and Objective Method to conclude Fluid Analysis (Gas/Water Reservoir), and Standardization of Fluid Identification

Abstract

Formation fluid identification (gas, oil, and water) is a crucial component of reservoir characterization to build geological modeling, presence of formation water and significant information in defining field development/perforation strategy. Fluid analysis tool has been used as standard logging tool for formation fluid identification. This fluid analysis tool consists of many sensors inside (Density, Capacitance, and Resistivity), base on these sensor and other parameter given, we can interpret the fluid at the real time operation, but also sometimes the information can give us the ambiguities or inconsistency result. The inconsistency of information caused by several factor; mud filtrate, mix fluid in that reservoir, gas water contact, the sensor is plugged by debris, low permeability, insufficient pumping time, different interpreter. Fluid scoring system has been developed in house, giving weight for each data or information that delivered by all sensors and parameters and applicable mainly for Gas and Water identification. In this methodology, 7 classifications with specific cut off value are used and at the end it will create score for final fluid interpretation; Density while pumping - segregation, capacitance, resistivity while pumping – segregation, compressibility, and pumping pressure trend. The objectives are to defined fluid ID easily, and speak at the same language (interpreter, data base). This methodology has been tested in delta Mahakam since 2014 with more than 300 FA data and the accuracy is 95%. This scoring system specifically use for gas and water reservoir only. Starting 2016, it has been sistematically implemented to classify formation fluid for all fields. It’s very helpful, powerful, decreasing confidence level of fluid uncertainity, and standardization in real-time operations.

AAPG Datapages/Search and Discovery Article #90354 © 2019 AAPG Asia Pacific Technical Symposium, The Art of Hydrocarbon Prediction: Managing Uncertainties, Bogor, (Greater Jakarta), Indonesia, August 7-8, 2019