Characterization of Arab Formation Carbonates Utilizing Real-Time Formation Pressure and Mobility Data

Abstract

AbstractWireline logging formation testing tools have long been used in the Arabian Peninsula for open hole formation pressure testing.Presently, a large number of wells are being drilled horizontally as producers and injectors, and often even as multilateral wells. This aggravates or prevents the use of conventional wireline logging technology. Formation pressure data are required to monitor the efficiency of production and injection for pressure maintenance.The Arab formation is a very prolific producing formation that consists of several members deposited in a carbonate shelf environment. Besides formation pressure, a representative permeability is an important element of the data acquisition. The Arab formation porosity and permeability are variable and dependant on original facies, mineralogy and diagenesis. Highly porous rock can have variable permeability dependant on a number of these factors.Conventional logs can show zones to be porous and hydrocarbon filled. These zones can be difficult to produce or inject due the presence of viscous heavy oil and tar. Therefore complicating the geosteering of the horizontal producers and injections. It has been found that the best way of recognizing such zones reliably, is through the utilization of real-time formation pressure testing data while drilling, preferably combined with magnetic resonance data.This paper will discuss examples of carbonate reservoir characterization utilizing formation pressure testing in combination with a full LWD logging suite. Operating procedures were specifically optimized to allow quality control of each acquired data set. An extensive, highly detailed, data set was transmitted to the end user, displayed real time both on the rig-site as well as in the operator datacenter to properly place the horizontal well for its intended objective.