DRILL STEM TEST INTERPETATION IN RESERVOIR CHARACTERIZATION USING PRESSURE DERIVATIVE METHOD WITH DIFFERENTIATION INTERVAL

• Main Author: RULLY CHAERUL SHOBAR (NIM : 22208048), M.
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/23141
• Institution: Institut Teknologi Bandung

X1and X2 reservoirs were in early phase of hydrocarbon field exploitation, several tests had been conducted to evaluate their hydrocarbon prospects and production feasibility. Drill stem tests were performed to get more information about the reservoirs. <br /> <br /> <br /> <br /> Objective of this study is to characterize and describe X1 and X2 reservoirs based on DST data. Several parameters to be determined are formation initial pressure pi, effective permeability k, skin factor s, and reservoir boundaries. The approach of analysis in well test interpretation uses pressure derivative method developed by Bourdet applying difference interval of numerical computation in plotting pressure derivative, superposition principle, and Horner’s method. The tests were conducted on interval 1802 – 1818 ftKB and 1832 – 1850 ftKB of X1 reservoir, also on interval 1513 – 1523 ftKB and 1940 – 1948 ftKB of X2 reservoir. The difference interval that used was 0.2 log cycle. <br /> <br /> <br /> <br /> Interpretation results show X1 reservoir at 1802 - 1818 ftKB has k = 146.,46 - 1730.25 md, pi = 685 - 687 psia, s = 9.82 - 13.36. And, at interval 1832 - 1850 ftKB, X1 reservoir has k = 104.95 - 125.49 md , pi =807.9 psia, s = 2.09 - 3.59 . These both intervals produce oil and small quantity of gas. The reservoir is located adjacent to some linear constatnt pressure boundary. X2 reservoir at 1513 - 1523 ftKB produces water and small quantity of gas. And, at interval 1940 - 1948 ftKB, the reservoir has 29.61 - 31.17 md, pi = 700 psia, s = - 2.99 up to -2.92 . Pressure derivative analysis on X2 reservoir detects a semi-permeable fault within it. Liquid pore volume cannot be determined since the flow regime on the tests were in transient period.