SPE 138698 Reservoir Test Optimization in Real Time with New Wireless Telemetry System A. A. Al-Nahdi, SPE, and T. S. Abo Elsaud, SPE, Saudi Aramco; E. Lemenager, SPE, M. Loth, SPE, F. Mabrouki, SPE and C. Acar, SPE, Schlumberger Copyright 2010, Society of Petroleum Engineers This paper was prepared for presentation at the Abu Dhabi International Petroleum Exhibition & Conference held in Abu Dhabi, UAE, 1–4 November 2010. This paper was selected for presentation by an SPE program committee following review of information contained in an abstract submitted by the author(s). Contents of the paper have not been reviewed by the Society of Petroleum Engineers and are subject to correction by the author(s). The material does not necessarily reflect any position of the Society of Petroleum Engineers, its officers, or members. Electronic reproduction, distribution, or storage of any part of this paper without the written consent of the Society of Petroleum Engineers is prohibited. Permission to reproduce in print is restricted to an abstract of not more than 300 words; illustrations may not be copied. The abstract must contain conspicuous acknowledgment of SPE copyright. Abstract A new wireless telemetry system has been field tested in a variety of conditions in Saudi Arabia with excellent reliability. This wireless system enables bi-directional communication between the surface and downhole tools during downhole testing (Drillstem Test (DST) / tubing conveyed perforation (TCP))) operations by using an electro-magnetic signal. The wireless telemetry is used to transmit bottomhole pressure and temperature to the surface and permits control of downhole tools. This paper will describe the operating principle of the wireless system, present examples of how real-time bottom-hole data have been used to optimize the testing operations and summarize the key benefits achieved with this new technology. The real time analysis of well testing data during well flow and shut-in was effective in adjusting the test duration. The wireless telemetry eliminated the need for well intervention, which simplified the operation and eliminated the possibility of loss of data. Introduction Exploratory well testing to evaluate hydrocarbon bearing zones in new fields is normally performed with a drilling rig on location. The main objective of well testing operations is to capture representative data on the reservoir and its fluids in the most cost and time efficient manner possible. A technology enabler for achieving this objective is a system that can transmit data from the bottom hole to the surface instead of relying only on surface data and waiting for downhole sensor retrieval at the end of the test. A new safe, reliable and efficient realtime data transmission system based on downhole electromagnetic telemetry has been developed for this purpose. The system uses electromagnetic waves to transmit data along the casing and through the formation to the surface, enabling the retrieval of reservoir pressure and temperature in real time during the test. In addition the system allows for control of downhole equipment such as the tester valve without having to apply annulus pressure as is conventionally done. The data streams from the reservoir to the surface and then through satellite transmission to the exploration group's operations center to allow the team to make effective decisions during the well testing operations. Equipment Description The wireless telemetry transmission is based on low frequency electromagnetic signal. The general arrangement of the system is presented in Fig. 1. The communication is bi-directional, from the surface to the bottom of the hole and from the bottom of the hole to surface. Telemetry performance depends on formation resistivity, completion geometry and wellbore fluids. Transmission ranges achieved during field testing from the hub to the surface have been between 6,000 to 10,500 ft. Installation of repeater unit(s) enables the depth range to be extended and helps to overcome the challenges of formation resistivity as shown in Fig. 1. The centerpiece of the downhole wireless system is the hub, which contains four pressure and temperature gauges and all electronics necessary for wireless transmission and reception. Each gauge that is mounted in the hub has independent battery and electronics for processing and recording of data. This arrangement guarantees redundancy and safeguards the data capture in case of any wireless telemetry system failure. The repeater has the same telemetry capabilities as the hub; however, with only a single