Pressure-Pressure Convolution Analysis of Multiprobe and Packer-Probe Wireline Formation Tester Data (2002)

Pressure-Pressure Convolution Analysis of Multiprobe and Packer-Probe Wireline Formation Tester Data M. Onur; M. Onur Istanbul Technical University Search for other works by this author on: This Site Google Scholar P.S. Hegeman; P.S. Hegeman Schlumberger Search for other works by this author on: This Site Google Scholar F.J. Kuchuk F.J. Kuchuk Schlumberger Search for other works by this author on: This Site Google Scholar Paper presented at the SPE Annual Technical Conference and Exhibition, San Antonio, Texas, September 2002. Paper Number: SPE-77343-MS https://doi.org/10.2118/77343-MS Published: September 29 2002 Connected Content Related to: Pressure-Pressure Convolution Analysis Using Wireline Formation Tester Data Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Get Permissions Search Site Citation Onur, M., Hegeman, P.S., and F.J. Kuchuk. "Pressure-Pressure Convolution Analysis of Multiprobe and Packer-Probe Wireline Formation Tester Data." Paper presented at the SPE Annual Technical Conference and Exhibition, San Antonio, Texas, September 2002. doi: https://doi.org/10.2118/77343-MS Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAll ProceedingsSociety of Petroleum Engineers (SPE)SPE Annual Technical Conference and Exhibition Search Advanced Search AbstractIn cases where flow rate data are not reliable, the need for flow rate in estimating permeability from wireline formation tester multiprobe and packer-probe pressure data sets can be eliminated by the use of the so-called pressure-pressure (p-p) convolution. The p-p convolution is based on the use of two different pressure data sets recorded at different spatial locations and, thus, enables one to perform parameter estimation without flow rate. In this work, we present a detailed analysis of multiprobe and packer-probe pressure transient tests by considering various p-p convolution options. Both single layer and multilayer (crossflow) systems are considered. Approximate equations that apply during spherical and radial flow for a vertical well in a single layer system for various p-p convolution options are derived. These equations indicate which parameters can be uniquely determined from p-p convolution. It is shown that p-p convolution analysis can sometimes provide nonunique parameter estimates. Also, we provide a flow rate extraction method that proves useful to check the validity of parameter estimates obtained from p-p convolution analysis. Two example tests, a synthetic multiprobe test and a field packer-probe test, are provided to illustrate the methodology and procedures developed in this work.IntroductionThe multiprobe (Fig. 1) and packer-probe (Fig. 2) wireline formation testers1–6 are well recognized and widely used tools in the industry to conduct controlled local production and vertical interference tests. These tools provide valuable information on undisturbed formation pressure, formation fluid samples, and estimates of horizontal and vertical permeability and wellbore damage. Further details about wireline formation testers, equipped with packers and multiple probes, can be found in Refs. 1–6.Permeability estimation from pressure data acquired by multiprobe and packer-probe formation testers has been the subject of several studies1–14 in the literature. Goode and Thambynayagam1 were the first to present comprehensive analytical models to study multiple formation tester pressure behaviors in single layer anisotropic systems. They showed that if flow rate is known at the sink probe, it is possible to determine horizontal and vertical mobilities (kh/µ and kv/µ) as well as the porosity-compressibility product (fct) from pressure data recorded at the horizontal and vertical probes by using pressure-rate (p-r) convolution.Fluid production at the sink probe or at the packer module can be provided by using a sample chamber module, flow-control module, or pumpout module.1–6 Because wireline formation testers often have no direct flow metering device, flow rate versus time data required in the analysis based on p-r convolution must be inferred from other measurements. In cases where the flow-control and/or pumpout modules are used, reliable flow rate data can often be determined from direct measurements of the piston displacement and tool characteristics.1–6 Zimmerman et al.2 noted that flow rate data could also be computed from sink probe pressure data using a modified form of a technique described by Samson et al.7 In a later paper, Goode et al.3 presented a similar flow rate estimation method based on the solution given by Moran and Finklea.8 The flow rate estimation methods given in Refs. 2 and 3 assume that the flow pattern around the sink probe is reasonably well approximated by spherical flow and require an iterative procedure that adjusts a lumped parameter involving horizontal mobility until the predicted volume of fluid recovered matches the recovered sample chamber volume. Keywords: equation, flow rate, spe 77343, artificial intelligence, pressure-pressure convolution analysis, sink probe, formulation, permeability, pressure transient analysis, drillstem testing Subjects: Formation Evaluation & Management, Pressure transient analysis, Drillstem/well testing, Formation test analysis (e.g., wireline, LWD) This content is only available via PDF. 2002. Society of Petroleum Engineers You can access this article if you purchase or spend a download.