已发表: 11/25/2015
已发表: 11/25/2015
In southern Mexico, an operator produces from naturally fractured carbonate reservoirs that generate a high water cut. The challenge is to selectively divert the treating fluid away from the watered-out natural fractures and limit water production after treatment, while improving the permeability of the oil-producing intervals. However, the variable intensity of natural fractures in each perforated interval creates an extremely high contrast in permeability, which in turn makes achieving uniform zonal coverage difficult. In this challenging environment, conventional acidizing treatments only resulted in a short-term increase in oil production and additional water production, but the operator required a solution that would improve long-term oil production without increasing water cut.
Schlumberger recommended OilMAX diverter to temporarily block the acid treatment from thief and high-water-cut zones and divert treating fluid from the natural fractures and fissures. Unlike conventional low-viscosity relative permeability modifiers, which do not adsorb onto the surfaces of generally oil-wet carbonates, OilMAX diverter is a viscous fluid that is able to adsorb onto both sandstone and carbonate formations, leaving the formation water-wet. This effectively increases the permeability to oil while decreasing the permeability to water, favoring oil rather than water production.
Over the course of 18 months, Schlumberger performed more than 100 successful treatments with OilMAX diverter for the Mexican operator. These treatments increased oil production by 11,000 bbl/d and decreased the produced water by 1,300 bbl/d, contributing to USD 1.7 million in savings related to water separation, treatment, and reinjection costs. The use of OilMAX diverter also reduced cleanup time by an average of two days, which saved 216 days of deferred production—the equivalent of USD 5.7 million.
Challenge: Increase long-term oil production without increasing water cut in naturally fractured carbonate reservoirs in southern Mexico.
Solution: Use OilMAX matrix acidizing diverter to temporarilyblock the treatment from thief and high-water-cut zones together with CLEAN SWEEP damage removal solvent systems and reactive treating fluids to stimulate target oil zones.
Results:
