Matra, an independent oil and gas exploration and production company with operations in Russia, is pleased to announce the following operations update for its Sokolovskoe Field:
Following pressure analysis and well testing which had indicated that Well-12 would benefit substantially from acid treatment, Well-12 was successfully treated with acid and cleaned-up with nitrogen, utilising a coiled-tubing unit. During clean-up and whilst pumping nitrogen the well produced at rates in excess of 1,000 barrels of oil per day (“bopd”).
During the latter stages of the operation however, the well appears to have developed a leak in the casing at a level above the main reservoir. This has allowed water to enter the well and is affecting well performance. The well is currently producing on natural flow and over the last two days averaged 720 barrels per day but with water cut increasing to around 30%.
Well-12 will continue to be produced until a workover rig is available – expected within the next two to three weeks. The length of the workover is unknown until the source of the leak is fully identified. The well will be returned to production on
completion of the workover.
Analysis of data from Well-13 indicated that acid treatment would be less effective than for Well-12. Bearing this in mind together with likely operational risks following the previous remedial cementation to shut-off water, acid treatment was not recommended for this well.
After cleaning out residual water with the coiled tubing unit and nitrogen, Well-13 is now producing 40-45 bopd on a 4.5mm choke with a wellhead pressure of 75 psi, without any indications of water production. Installation of a downhole pump
in Well-13 at a later date is likely to increase production to the 80-90 bopd level.
Well-13 currently has leased production equipment on site. This equipment lease ends on June 10th and the well will be shut-in whilst suitable production equipment is manufactured (a two to three month shut-in is anticipated). The well
will then be returned to production.
Matra’s Managing Director, Peter Hind commented: “The acid treatment has been very successful in improving productivity in Well-12, and the well appears to be capable of oil production under natural flow of close to 1,000 barrels of oil per day.
An apparent leak in the casing in the well has allowed water into the system and needs to be repaired before confirming this result. A workover rig will be mobilised to the site as soon as the relevant equipment can be sourced.
It’s pleasing to see that Well-13 is producing oil without any signs of water. Whilst acid treatment may have improved productivity of this well a little, there were significant operational risks associated with this and accordingly, such treatment was not recommended. The fact that both wells were drilled to meet our licence obligations means that
they were not ideally configured for production. This has caused various operational difficulties that can be eliminated by design changes for subsequent development wells.”