Abstract

Moriche is a heavy oil field operated by Mansarovar Energy Colombia Limited (MECL), structurally located in the western flank of the Middle Magdalena Basin; near Teca, Nare Sur and Jazmín fields which were the first fields that applied CSS as enhanced recovery method in Colombia. For Moriche Field to be an economically attractive development it was necessary to use thermal methods to enhance oil recovery. The Moriche oil production comes from a multilayer reservoir called B zone, a shallow reservoir with high viscosity oil (800 cp to 2600 cp); formation pressure from 600 to 1200 psi and low formation temperature from 100-120 °F. The thin sandstones found are a result of the fluvial depositional environment and have a high content of smectite and illite interbedded with shales which makes them highly stratified.

Cyclic steam stimulation in Moriche began in 2009 applying the experiences of the fields mentioned before; most of the stimulations presented a low response after CSS. Critical events were taking place and some challenges to solve: 1.) Low steam injectivity, rapid well pressurization and very high decline rate. 2.) Low steam quality at the bottom hole. 3.) Formation damage during drilling and steam injection due to high content of smectite. 4.) Selective steam injection in open hole completions. 5.) Implementation of new technologies in EOR process.

Several numerical simulation runs were made to understand the heat transfer process, the production behavior and to define the best steam injection parameters and procedures to ensure a good response after CSS, followed by full field numerical simulation model, laboratory test and implementation of new technologies in EOR.

This paper highlights CSS pilots done to optimize steam injection and the full field implementation in order to increase well productivity; the data analysis and laboratory procedures to identify formation damage and its implementation and the importance of simulation modeling in thermal process.

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