The C7 reservoir, located in Casanare Basin, not only exhibits serious formation consolidation problems, but the producing zone is also close to the oil/water contact. Most of the workover interventions have been focused on sand- and water-production issues. A solution developed to obtain hydrocarbon production that combines sand-control and water-control techniques, without additional services to clean the sand or change the production pump, is presented in this paper.

Numerous methods for this purpose exist in the industry, such as mechanical sand control methods, chemical treatments, and combinations of both. These are typically applied according to best practices with consideration of the associated costs.

The sand-control technique presented in this paper has been applied for three consecutive years in the area of Casanare, Colombia and has proven to be successful. This technique consists of pumping linear gel at high rates to place the proppant into the formation; in some cases, up to 40 sacks/ft (experiences in other regions mention 3.5 sacks/ft). In some cases, because of the proximity of the water, it was decided not to fracture to prevent the influx of water.

To increase the amount of proppant placed in the formation, a combination of two techniques, which have each proven to be successful individually, has been implemented. These techniques are: (1) use of a relative permeability modifier (RPM) to control the water influx and (2) high-rate pumping of linear gel to place proppant.

The combination of the RPM treatment and sand-control technologies designed for each particular area has set a new standard for sand-control operations in the area.

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