Wireline-Conveyed Through-Casing Formation Tester Preserves Casing Integrity

Abstract

Wireline-Conveyed Through-Casing Formation Tester Preserves Casing Integrity K.A. Burgess; K.A. Burgess Schlumberger Search for other works by this author on: This Site Google Scholar T.D. MacDougall; T.D. MacDougall Schlumberger Search for other works by this author on: This Site Google Scholar R.W. Siegfried; R.W. Siegfried Gas Research Institute Search for other works by this author on: This Site Google Scholar T.G. Fields T.G. Fields Schlumberger Search for other works by this author on: This Site Google Scholar Paper presented at the SPE Eastern Regional Meeting, Canton, Ohio, October 2001. Paper Number: SPE-72371-MS https://doi.org/10.2118/72371-MS Published: October 17 2001 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Get Permissions Search Site Citation Burgess, K.A., MacDougall, T.D., Siegfried, R.W., and T.G. Fields. "Wireline-Conveyed Through-Casing Formation Tester Preserves Casing Integrity." Paper presented at the SPE Eastern Regional Meeting, Canton, Ohio, October 2001. doi: https://doi.org/10.2118/72371-MS Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex Search nav search search input Search input auto suggest search filter All ContentAll ProceedingsSociety of Petroleum Engineers (SPE)SPE Eastern Regional Meeting Search Advanced Search AbstractAdvances in formation tester technology and a novel electromechanical drilling technique have provided the oil industry with a new modular through-casing formation tester. The wireline-conveyed tester, which determines formation pressure and fluid content behind casing, has been developed in a joint project conducted by the Gas Research Institute and Schlumberger. More than 200 Tcf in gas resources are estimated to exist behind casing in the United States alone. To facilitate evaluation of these potential reserves, the tool was designed to make a hole through the casing, measure formation pressure, take fluid samples and then reseal the hole. This paper describes the tool features applications and field test results.Primary applications include detection of bypassed hydrocarbons, evaluation of potential pay prior to well abandonment, and formation testing under conditions where openhole testing and sampling are not feasible. Reservoir management applications include production monitoring, especially waterfloods and CO2 floods, and economic evaluation for selling and booking reserves. Secondary applications include detecting gas-collector zones in gas storage wells, and injecting or producing through a few small drilled holes (i.e., limited-entry steam injection).The tool uses a flexible drill shaft to drill holes several inches deep through casing, cement and formation. Pretests, involving pressure drawdown and buildup flow periods, are performed as pressure is measured with both a crystal quartz gauge and a strain gauge. If desired, a formation fluid sample can also be taken at this time. A reliable mechanical plug seals the drilled hole in the casing, creating an effective seal to at least 10,000 psi of differential pressure (either direction). This serve was introduced in October 2000 and is now completing field trials. This novel technique for measuring pressure and taking samples through casing provides the ability to assess pay without perforating the well and facing costly and often problematic cement squeeze jobs.IntroductionSince the 1950s wireline formation testers have evolved into sophisticated modular tools. The early formation testers had a large rubber pad through which two shaped charges were fired into the formation. Hydrostatic mud pressure and formation buildup pressures were measured with downhole recorders. Fluid flowed from the formation through a single flowline in the tool into a sample chamber. After the sample chamber was filled, the tool was retracted and brought to the surface. These tools made a single pressure measurement and recovered a single sample per trip.In the 1960s, the first cased hole formation tester1 to measure formation pressure and recover a reservoir fluid sample was developed. The formation interval tester incorporated a flowline check valve, which permitted the recording of pressure buildups before and after sampling into a single sample chamber. To minimize rig time costs, a formation squeeze adaptor2 was developed to cement the perforations made in the casing. Estimates of well productivity from the measured pressure and recovered sample data were reliable only under certain circumstances.3In the 1970s a formation tester4 that could take multiple samples per trip was developed to improve efficiency. This tester provided quick pressure profiling via the capability of successfully setting the tool at different depths. In addition, two sample chambers in the tool gave the flexibility of selectively taking two samples per trip in the well or to "clean up" the formation before collecting a sample at one depth; i.e., "segregated" sampling. Interpretation techniques5,6 were also developed to analyze the pressure transient data recorded with the wireline formation testers.In the 1980s a cased-hole formation tester was developed based on the technology of the repeatable tester. Two selectable shaped charges fired through two pressure ports permitted two pressure tests and two sample tests per trip in the cased hole. Keywords: pressure transient analysis, formation testing, seal test, through-casing formation tester, tester, log analysis, upstream oil & gas, module, pressure measurement, formation tester Subjects: Formation Evaluation & Management, Open hole/cased hole log analysis, Pressure transient analysis, Formation test analysis (e.g., wireline, LWD) This content is only available via PDF. 2001. Society of Petroleum Engineers You can access this article if you purchase or spend a download.