Coiled Tubing for SlimHole Cementing and Completing

摘要

Current trends in the oil and gas industry are focusing morernheavily on operational efficiency and cost reduction than everrnbefore. Therefore, operators and service companies arerninvestigating any technique that offers possibility forrnimprovement in these areas, and this explains the recentlyrnrenewed interest in the monobore and slimhole concepts.rnThe most obvious savings are those that relate to:rn? the size of the rig required to drill the holern? the amount of well control material used during therndrilling of the holern? the quantity of cement required to cement the casingrnstring in placern? the size and quantity of tubing and casing required torncomplete the wellrn? the discharge of drill cuttings would be dramaticallyrnreduced.rnThis paper will review a new equipment design that isrnideally suited for use with coiled tubing to perform a cementrnjob in slimhole wells.rnThis innovative technique is performed with 2-in. coiledrntubing. A special device, which is made up with an educatedrnJ-slot and a 2.55-in. seal at the end of the coiled tubing, willrnengage and disengage automatically from a seal borernreceptacle that is placed at the end of the 3-?-in. casing string.rnThis tool is retrieved, easily redressed and re-used. It canrnbe sheared so that the coiled tubing can be pulled in the eventrna catastrophic event occurs during the cement job.rnThis tool reduces the contamination of cement. In addition,rnit offers an economical method for cementing in scenarios inrnwhich a standard cement job cannot be performed. Forrnexample, when a control-line-activated landing nipple is usedrnin the casing/tubing string, there is risk of depositing cementrnin the landing nipple bore and plugging the control line whenrnusing traditional cementing techniques.rnThis paper describes the operational procedures, benefitsrnof the system, and a slimhole completion design adopted byrnENI-AGIP to take advantage of the benefits of the system.