Different methodologies for obtaining a permeability distribution in the Misoa Formation, Venezuela

Abstract

Two methodologies have been applied for evaluating formation permeability using log and core data. One methodology is based on a modified Kozeny-Carmen equation and the concept of mean hydraulic radius. The other methodology involves a permeability correlation as a function of porosity and grain diameter based on systematic packing. These two methodologies have been used to determine a permeability profile in the Misoa Formation, Venezuela. Formation permeability controls the strategies involving well completion, well stimulation and reservoir management. The tools we normally use to estimate values of permeability are logs, cores, well tests and production data. One can also use seismic data to assist in computing the permeability distribution between the wells. The most economic method to evaluate formation permeability will usually be from well logs. In this research, we used logs and special core analyses to determine the permeability correlation in a specific reservoir located in the VLE-196 area of Block V in Lake Maracaibo, Venezuela. The VLE-1 96 area has production from the B, C2, C3, C4 and C5 reservoirs. The data from logs, cores, well tests and production are plentiful, but these data have never been correlated in an effort to compute the permeability distribution. Knowledge of the permeability distribution in the "C" sand reservoirs in the VLE-196 area would be of significant benefit to the operating company, P.D.V.S.A. In this research, I applied and compared the Amaefule et aL and Berg methodologies with the standard regression method for correlating permeability. I used log and special core data from two wells, VLE 1063 and VLE 677, in the VLE-1 96 area. The final step was to propose the best permeability correlation in the C-4 and C-5 sands in the VLE-1 96 area. According with the results combining the Amaefule method with a strong statistic analyses give a good permeability correlation in the C-4 and C-5 intervals. Reservoir Rock Properties", GCAGS Trans. (1970) 20, 303. Amaefule, JO., Altunbay, M, Tiab, D., Kersey, D.G., and Keelan, D.K.: 'Enhanced Reservoir Description: Using Core and Log Data to Identify 1-iydraulic (Flow) Units and Predict Permeability in Uncored Intervals/Wells", paper SPE 26436 presented at the 68th Annual Technical Conference and Exhibition, Houston, October 3-6, 1993.