Experience tells us that progressing cavity pumping is the logic choice for producing heavy sandy fluids. Nevertheless, under these conditions PCPs suffer from blocked suction, sanded pump and low runlife. In order to overcome these issues two technologies were tested simultaneously: charge pumps and medium nitrile elastomer.

The fields involved in this study are El Corcobo Norte, Cerro Huanul Sur, El Renegado, Jagüel Casa de Piedra and Puesto Pinto which produce from the Centenario Formation and are located in the Neuquen Basin. These are non-consolidated sandstone formations with an oil gravity of 18 °API that are produced following CHOPS philosophy (Cold Heavy Oil Production with Sand), where sand production is deliberately maintained through time.

In 2010 the first charge pump PCP was installed, followed by six more wells in the course of two years. This system proved to be an alternative for high sand cut wells (4-5% continuous and up to 25% slugs) and also reduced by half flush-by interventions due to sanded pump.

Also in 2010 started the trials with a softer elastomer (medium nitrile).The sanded pump failure rate was lowered (comparing pumps with the same volumetric capacity and in the same well), reducing downtime and hence increasing production. These pumps also showed higher operating efficiency and longer run life than high nitrile pumps.

These results encouraged us to integrate both technologies, resulting in the installation of charge pump PCPs with medium nitrile elastomer during the last quarter of 2012. In 2013 we will field test pumps with enhanced geometry. This is all part of a combined effort for finding reliable and cost effective solutions for challenging applications.

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