Showing papers by "Abu Dhabi Company for Onshore Oil Operations published in 1997"

Cementing Through Coiled Tubing Decreases Well Completion And Testing Costs

Abstract: Conventional applications of cementing through coiled tubing, which has been around over the last decade has now become a standard practice that includes zonal isolation, casing repair, water or gas shut off and zone abandonment.The use of this technique being advantageous both technically and economically, have been extended to include multizone well testing. This paper describes how the use of good practices of cement through coiled tubing design and placement helps optimize the overall cost of a well testing operation. The cementing through coiled tubing technique is finding more and more applications with the improvement and fine tuning of the design and placement practices. Apart from its technical advantages of accurate placement, reduced contamination, single continuous pipe string with less risks of leaks, coiled tubing cementing has financial benefits from leaving the completion in the well, requiring small quantities of kill fluids, and not having to mobilize a workover rig for most of the applications. This paper describes how the accuracy of cement placement and the effectiveness of the perforations isolation, along with the optimization of the number of test strings run and the zones tested separately through the same string contributed, during a multizone well testing program, to a major technical success and cost saving. The major factors considered in designing the cement slurry. along with the placement techniques used to achieve cement plug accuracy and isolation efficiency are elaborated. A comparison between the use of the conventional zone abandonment and the coiled tubing technique in multizone well testing is also shown to illustrate the cost savings involved.