The last workover operation done in Well JM Ward B#31 was Re-perforated & stimulation and has been done on August 2011, data before workover was; BWIPD = 940 @ 1040 PSI, Data after the workover operation illustrated as follows; 2999 BPD @ 760 PSI.
An obvious decline in the daily injection rate with noticeable increase in the WHP value due to very low permeability of the formation zone and formation matrix damage status that in need to a special chemical treatment. Current data is 1321 BWIPD @ 980 PSI.
The well bore radius (rw) is generally between ‘’0.3 to 0.4’’ ft. The critical matrix is the place where most of the permeability damage occurs. The radius of the critical matrix (altered damage rd.) is generally 0.75 to 1 feet (Fig.1). Permeability damage in this area can significantly reduce production / injection. It is recommended to stimulate the interested section to penetrate with the chemical solution through the well bore and damaged area.

Semi-quantitative analysis obtained by X-Ray diffraction for scale sample
MINERALOGY (WEIGHT%)
Mineral Name	Barite	Weight(%)
Percentage	100	100
Crystal lattice	Orthehombic
Chemical Structure	BaSO4
Crystal Shape

Challenge

Scale interpretation that has been done on water analysis reports collected from both of PK and produced water suggested that the mineral content of the Scale to be Barite scales, the Stiff Davis Index (Barium Sulfate SI) signifies a scaling potential due to the positive scaling condition exist, the positive SI indicates the super saturation condition that lead to significant damage subsequently the permeability being are much lower than calculated.
The chemical treatment and Scale Removal is expected to clean the perforation tunnels from the scale and any damage exists (positive skin) that may be lodged in it.

Solution

SCSR-05 Chemical squeeze in the formation for permeability enhancement Through Bull Heading operation

The last data for well# WARD JM B#31 which showed the injection rate reach to 1813 BPD with 960 psi comparing with 1223 BPD before the job with the same WHP. Based on official reports.
The job proved that SCS chemical is not damaging fluid like the normal acid and get nearly 50% increase on the injection rate