Abstract
In the past few years, research has been conducted at Texas A&M University on steam-propane injection to enhance oil recovery from the Morichal field, Venezuela, which contains 13.5 ⁰API gravity oil. Experimental results show that a 5:100 propane:steam mass ratio efficiently accelerates the beginning and peak of oil production by 20 % and 13 % pore volume steam injected (cold water equivalent), respectively. This experimental study was undertaken to better understand the role of propane in accelerating oil production and to compare the performance of steam-propane injection versus steam injection alone on an intermediate crude oil of 21 ⁰API gravity. Eight experimental runs were performed: three pure steam injection runs, three steam-propane injection runs with 5:100 propane:steam mass ratio, and two steam-methane injection runs with 5:100 methane:steam mass ratio. Main findings of this study may be summarized as follows. First, propane used as an additive in steam injection accelerates the start and peak of oil production by about 12 % and 13 % of the steam injected pore volume respectively, compared to steam alone or steam-methane injection. Second, propane behaves as a miscible solvent reducing the produced oil density. It appears to act as a carrier gas by picking up the lighter oil fractions and transporting them ahead of the steam front where they condense, lowering the viscosity of the oil. Third, as an additive in steam injection, methane has a low miscibility with the oil. From the analysis of the produced oil samples, it appears that oil density and viscosity are similar to those of the initial oil in the steam-methane runs. Fourth, oil recoveries for the runs were in the range of 52-59 % of original oil in the cell, based on the 150 minutes run time. Experimental results to date indicate steam-propane injection to be a promising EOR technique. However, further research on a wide range of oil gravities and steam:propane mass ratios needs to be conducted to fully understand the process.
Tinss, Judicael Christopher (2001). Experimental studies of steam-propane injection to enhance recovery of an intermediate crude oil. Master's thesis, Texas A&M University. Available electronically from
https : / /hdl .handle .net /1969 .1 /ETD -TAMU -2001 -THESIS -T568.