Fula oil field is composed of unconsolidated sandstones, buried as deep as 3500ft, with high porosity (31%) and permeability(2 Darcy), producing viscous oil with 19-21°API on the south flank of Muglad Basin. It is well-known that under proper conditions formation flow characteristics can be improved by non-thermal massive sand production and foamy oil behavior, referred to CHOPS.

Integrated well completion strategies with CHOPS were used to increase heavy oil production. Limited sand influx provides a means for effective sand control while eliminating the need for conventional sand control processes. The principle of limited sand flux is ‘coarse sands controlled and finer sands produced’, which is using the screen liner to inhibit 0.5mm or larger sands flowing into the wellbore, in addition, the rest smaller solids can be produced to the surface by viscous oil.

Experiments were conducted to study the capability of lifting sands by crude oil. It showed that the sand of 0.9mm can be allowed to move up with heavy oil to the surface while 510 mPa.s of viscous oil is lifted in 3 1/2 in tubing. Using progressing cavity pump deliberately initiated sand influx but only 15% solids were controlled to form wormhole to improve permeability of the pay zone.

This paper describes initial field test results of the new system that 20 heavy oil wells were equipped with PCP which is helpful for handling sanding effectively. The sand cuts range from 0.1 to 12% by volume. Average oil rate of each well is up to 580bopd from 175bopd before CHOPS. The best well can produce as much as 1200 BOPD. Oil production has reached to 2,450,000 bbl/y with attractive result.

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