Abstract
The excess of water production from oil wells in several areas of Khafji field is a subject of concern for reservoir management. Water shut-off techniques are common practices to reduce water production which is resulted in well productivity improvement. An oil producer well-A, was worked-over on February 22, 2006 to conduct a water shutoff technique on existing perforation intervals utilizing a cement squeeze. Several logs such as RST and Gamma Ray were carried out to identify the fluid movement. Then, the well was produced with an oil rate of 1,200 BOPD and a rapid increase of water cut of 60%. The well was still unstable in terms of rate due to high water cut. The well was considered for rigless work-over to control the water using Mechanical Through Tubing Bridge Plugs (MTTBP) to isolate the lower two perforation sections. After setting the Bridge Plug with 8 ft. of cement above the plug, the well was revived with production stream. During the first 24 hrs of well production, the treatment result was not as expected which resulted in 100% water cut. A discussion was made by reservoir management engineer to continue of production for additional 24 hrs. With time, the well showed a positive result with a reduction in water up to 95%. It is recommended to keep the well to be produced over 21 days with final results showed the well revived with an oil production of 1,500 BOPD with zero water cut.
The result showed a successful water shutoff technique and scenario to retrieve the well with 100% water cut produced after treatment. Challenges, intervals selection, design criteria, lessons learned, and results of the water shutoff technique will be discussed in this paper.
