ABSTRACT

The management of unproductive water has been one of the major challenges facing the petroleum industry. Globally, it has been estimated that about 210 million barrels of water are produced daily accompanied with 75 million barrels of oil worldwide. Consequently chemical shut off methods, mechanical methods and other methods have been developed and deployed to control the excessive water production in oil and gas industry.

In this study, a review of the water shut off treatment methods and reduction techniques was done. The major sources of water problems identified and categorized based on the causes of water production and the order of treatment difficulty. The methods of diagnosing excessive water production were also review.

Four (4) case study of selected four oil wells each from Reservoir, RW, RX, RY and RZ oil field of the Niger Delta region, were evaluated with production data obtained from these reservoirs with a view to investigating failure and success of after treatment of the wells using chemical and mechanical methods, by comparing the methods based on four broad categories which includes performance time, efficiency, cost and operability.

Post mechanical water shut off treatment methods deployed in Well 9T and in Well 11T results in an increase of oil production from an average of 52% to 88% and 41% to 90% respectively while the chemical water shut off methods applied to Well 6T and Well 13T lead to a decrease in oil production from an average of 57.77% to 28% and 61% to 21%.

Therefore, from the performance of the two methods, mechanical methods proves to be more efficient based on its performance time, performance output and cost associated with carrying out the operation.