RESERVOIR LIMIT TESTING FOR FRACTURED WELLS (1978)

Reservoir Limit Testing For Fractured Wells Alain C. Gringarten Alain C. Gringarten Flopetrol Search for other works by this author on: This Site Google Scholar Paper presented at the SPE Annual Fall Technical Conference and Exhibition, Houston, Texas, October 1978. Paper Number: SPE-7452-MS https://doi.org/10.2118/7452-MS Published: October 01 1978 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Get Permissions Search Site Citation Gringarten, Alain C. "Reservoir Limit Testing For Fractured Wells." Paper presented at the SPE Annual Fall Technical Conference and Exhibition, Houston, Texas, October 1978. doi: https://doi.org/10.2118/7452-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 ABSTRACTThe purpose of the paper is to extend reservoir limit test analysis techniques to fractured wells. By deriving the pseudo-steady state pressure functions for an unfractured and a fractured well at any position of a closed rectangle, it is shown that shape factors for fractured wells are not readily obtainable from the ones for unfractured wells.Exact analytical expressions of shape factors for fractured and unfractured wells in a closed rectangle are presented, along with graphs of these quantities versus appropriate parameters.Type curves for a fractured well at the center of a closed rectangle are also provided. Both uniform flux and infinite conductivity fractures are considered.The curves presented in this paper are then used with actual field data for estimating the drainage volume of a fractured well and the shape of the well drainage area.INTRODUCTIONReservoir limit tests, introduced by Jones1, are commonly used for evaluating the reservoir volume communicating with the well. The analysis is based on the fact that the well pressure during pseudo-steady state flow is a linear function of the production time:Equation 1whereEquation 2andEquation 3A represents the drainage area (in sq.ft) and CA the drainage area shape factor. Eq. 1 may also written in dimensionless form as:Equation 4withEquation 5andEquation 6A cartesian plot of bottom-hole flowing pressure versus production time will thus yield a straight line after pseudo-steady state conditions are reached. The slope of the straight line (Eq.2) may be used to estimate the connected reservoir drainage volume:Equation 7and the drainage area, if Ï?h is known.The shape of the drainage area may be estimated from the pseudo-steady state cartesian plot if pressure data are also available from an infinite acting flow period2. These are used to determine the semi-log straight line slope:Equation 8and p1hr. The system shape factor is then obtained from:Equation 9By comparing the calculated CA with the ones published in the literature for various drainage area configuration3–5, it is possible to estimate the shape of the drainage area. Keywords: rectangle, drillstem/well testing, Gringarten, Drillstem Testing, vertical fracture, analytical expression, shape factor, wellbore radius, Reservoir Limit Testing, straight line Subjects: Formation Evaluation & Management, Drillstem/well testing This content is only available via PDF. 1978. Society of Petroleum Engineers You can access this article if you purchase or spend a download.