Perpustakaan Digital ITB

As one of the most prolific reservoir in the world, naturally fractured reservoir has been studied over the years. Over 50% hydrocarbon reserves trapped in this type of reservoirs. These type of reservoir has a particular characteristics. An ideal system of naturally fractured formation is composed of a heterogeneous system of vugs, fractures, and matrices. Two key parameters were introduced by Warren and Root to characterize naturally fractured reservoir: Dimensionless storage coefficient (?) and inter-porosity flow parameter (?). Well Testing is a method that can be applied to obtain these naturally fractured reservoir characteristics. The test involve constant rate production or shut in a period of time. Interpretation of these tests can be determined from two methods, semi-log analysis (conventional analysis or straight line analysis) and type curve matching. A new methodology proposed by Djebbar Tiab and Thomas Engler, called Tiab’s Direct Synthesis Technique, is used for interpretation of pressure tests in naturally fractured reservoir. The technique involves analysis of the characteristic intersection points and slopes of various straight lines from a log-log plot of pressure and pressure derivative data without using the type curve matching regression procedures. Tiab’s Direct Synthesis will be applied to gas well test interpretation in naturally fractured reservoir. Pressure tests are given from X Field which produces from basement zone and contains dry gas. The interpretation using pseudo-pressure approach conducted in this analysis. Several parameters obtained such as fracture permeability, storage coefficient, inter-porosity flow parameter, skin factor, and wellbore storage. A comparative analysis with type curve matching method is presented. The results between direct synthesis and type curve matching are almost similar.