Penentuan Swelling Factor dan Tekanan Tercampur Minimum untuk Penerapan Injeksi Gas Karbondioksida di Lapangan Minyak

Abstract

Oil swelling and minimum miscibility pressure (MMP) are two important factors of carbondioxide (CO₂) gas displacement mechanism occurred in the reservoir relate to application of CO₂ injection in the field to enhance oil recovery. In this paper determination of swelling factor was conducted using PVT cell, where recombined fluid injected and conditionally at the reservoir temperature. While, determination of MMP between crude oil samples with carbondioxide gas conducted using three methods, i.e. empirical equation, correlation methods and laboratory experiment using slimtube. Based on the results of swelling test during injection CO₂ gas processes until 46.82% mole, shows that bubble point pressure is increasing gradually from 410 Psig through 2200 Psig, and swelling factor was also increase from 1.0 through 1.442. The results of minimum miscibility pressure based on the empirical equation is 2807 Psig, correlations of Cronquist is 2301 Psig; Yellig & Metcalfe is 2490 Psig; Holm & Josendal is 2750 Psig, otherwise based on the laboratory measurement using slimtube is 2800 Psig. Determination of MMP using Holm & Josendal correlation is more approximate to the result of laboratory analysis. Furthermore, based on the value of fracture pressure of Layer F is 2200 Psig and MMP is 2800 Psig, hence the application of CO₂ gas injection in the field only could be conducted as immiscible flooding.