Application of Telemetry Technology In High-Pressure Wells To Improve Data Accuracy in Drill Stem Tests

Abstract

Drill-stem testing (DST) has been used for many years in the oilfield to establish reliable reservoir characterization. The DST data are used to provide estimated production, fluid analysis, and to help design the final completion and production facilities.More recently, discoveries in abnormal pressure gradients and deep formations have not only pushed the capabilities of traditional equipment and procedures, but also increased the safety hazards inherent to DST operations. At surface, high pressures, the presence of H 2 S, and toxic well fluids increase the difficulty in deployment of real-time data acquisition and sampling equipment via wireline. Downhole, the high hydrostatic pressures normally found in deep environments can hinder the operation of the downhole tools. Often, to achieve high hydrostatic pressures, the operator is forced to use drilling muds which may have very low pressure transmissibility and solids problems that interfere with annulus-pressure/pulse-response tools.The need to improve the quality of information gathered during DSTs in hostile environments has driven a major oilfield engineering company to research concepts that could improve capabilities of traditional DST systems.This research led to the development of a novel telemetry system that uses acoustic bi-directional acoustic transmission through the tubing string. This system, compact and easy to deploy into the well, provides real-time data-acquisition flexibility in various depths in the string, enabling the constant monitoring of the wellbore conditions throughout the DST. It's design, applications, and ability to simplify job procedures, reduce risks, and improve quality of information when linked to data acquisition and tool operation, will be the focus of this paper.This new system provides greater efficiency in acquiring data in deeper, high-pressure DST environments than are currently possible with the standard methods.

First Real-Time Drill-Stem Test in Deepwater Using Fully Acoustic Telemetry Monitoring and Control of the Well

“…This need posed a challenge for the annulus-operated tools, and as a solution, alternatives such as acoustic telemetry systems have been researched in the hopes that this technology could overcome this problem. (Haddad, J. et al, 2010) The current wireless system generates the data acquisition required to fully characterize the reservoir while also providing the capability to control the tester/circulate valve and downhole sampler. The system has been proving to be a reliable and trustworthy solution for DST operations in all environments.…”

“…In a job performed for a large NOC in South America in 2009 the system played an important role in the operations as a result of unexpected production of sand during the job, which hindered the deployment of a wireline system to the desired depth for data retrieval. (Haddad, J. et al, 2010) • Effective bottomhole PVT fluid sampling: If bottomhole samplers are included in the string, the retrieval of dynamic information of the pressure and temperature in real time can provide assurance that the target is a single-phase fluid before actuating the downhole samplers. • Assurance of data: This wireless system will help assure that needed data are collected; also, by doing real time quality control of the data, all necessary analyses can be done, and the operator can be assured of the accomplishment of well test objectives before the string is retrieved.…”

Simulation and experiment of vibrational or acoustic communication in mining and oil-gas drill strings

“…Although the vibrational method was introduced previously, because of the lack of an efficient transducer the method was not popular. Nowadays, piezoelectric ceramic technology has become more advanced, so the method of acoustic telemetry is beginning to gain commercial popularity (Haddad et al 2010;Dias et al 2014;Kreuzer et al 2014). In acoustic telemetry, the medium of pressure wave transmission is the solid steel pipe rather than viscous liquid as in MPT, so it has less attenuating factors.…”

Experimental Results and Proposed Electromechanical Model for Vibrational Communication in Mining and Oil-Gas Drill Strings

“…The vibrational method and theories have been known from the beginning of the MWD, but because of the lack of an efficient transducer, the method did not flourish. Currently, because of advancements in piezoelectric ceramic technology, the method has resurfaced and is beginning to gain commercial popularity [6][7][8][9].…”