C OMPLETIONS Managing retrieval of triple-zone intelligent completions in offshore extended-reach well By L. Izquierdo, T.U. Ceccarelli, Schlumberger; G.P. Hertfelder, Items to be replaced K. Koerner, Plains E&P; S. Pace, Chevron Description Comments AN INDEPENDENT operator The multiport packer is a cut-to-release packer, meaning offshore California has successfully achieved triple-zone intelligent well com- Multiport isolation that the mandrel is severed in order to release the packer. pletions in an extended-reach drilling packer, 7 in. x 3.5 in. This, in conjunction with the replacement seals, means that (ERD) campaign in its Rocky Point field. it’s uneconomic to redress this packer. To date, two workover interventions The multiport packer is a cut-to-release packer, meaning have been performed in five deployments Multiport production that the mandrel is severed in order to release the packer. in the field, of which three are currently packer, 7 in. x 3.5 in. This, in conjunction with the replacement seals, means that fully operational. it’s uneconomic to redress this packer. The Rocky Point reservoir is a highly 3 ½-in. swivel Uneconomic to refurb this item. fractured carbonate and can rapidly initiate water production. Achieving It may be possible to salvage a small number of the protec- zonal isolation in the wellbore and at the 3 ½-in. cable protector tors retrieved from the well, but based on experience, 80% reservoir level is critical. During the pro- of the protectors will need to be replaced. duction stage, it was recognized that two of the wells did not achieve the required It may be possible to salvage a small number of the protec- zonal isolation evident by increasing 4 ½-in. cable protector tors retrieved from the well, but based on experience, 80% water cut. The operator decided to of the protectors will need to be replaced. retrieve these completions to conduct Due to the uncertainty of the condition of the control lines liner cement repairs. Hydraulic control lines and the inability to perform suitable integrity tests, it is These triple-zone completions are recommended to replace all the control lines. controlled by 3½-in. tubing-retrievable Cable splice will be required to have connectivity between flow-control valves, open/close and Electric cable splice the gauges. Removal and redress of the blocks is not multiple-position, that work with dedi- cated gauges for monitoring of pressure economical. and temperature. Each of the productive Due to the uncertainty of the condition of the instrument zones was isolated by three multiple- Tubing electric cable cable and the inability to perform suitable integrity tests, it port retrievable production packers. is recommend to replace all the instrument cable. The main challenges in retrieving these completions were: Items to be refurbished • Conveyance of the cutting tools to depth (due to ERD profile). Description Comments • Accurate location of the cutting tar- Tubing retrievable subsurface Requires replacement of all elastomers, full FAT and gets (+/- 6 in. at 18,000 ft MD). safety valve re-certification. • Severing all control/electric lines and Thread inspection, pocket inspection. Valves pulling all three packers in the same Gas lift mandrel system removal and inspection, redress seals, valve set-up, trip. valve loading and function test. • Re-dressing and re-running the com- 3 ½-in. tubing retrievable flow pletions within two weeks of retrieval. control valves – open/close and Replacement of all elastomers, function test and FAT. This paper describes the feasibility variable of deploying explosive jet cutters by Monitoring system – gauges Thread inspection. Function test and cable head pumping wireline conveyed assemblies and mandrels redress, re-calibration. to locator profiles above each packer, which allowed for simple, cost-effective Pipe accessories Thread inspection and hydro-test. intervention, avoiding costly mobiliza- tion of tractors or coiled tubing. Lessons (e.g., minimum distance of control valves tions), there is limited experience with learned are shown on how completions from packers) that will be implemented the managed retrieval of these complex components were affected by the cut- in future installations. systems. This paper highlights the ting operation and the extent of their methodology, procedures and lessons refurbishment before re-completion. The INTRODUCTION learned associated with the retrieval of paper also identifies modifications to intelligent completions installed in ERD Even though the intelligent completion intelligent completion design parameters wells. industry is maturing (500-plus installa- 132 September/October 2008 DRILLING CONTRACTOR C OMPLETIONS ERD wells complicate retrieval due to The initial completion was installed as a) The workover program preparation the fact that the applied forces down- a triple-zone intelligent completion in scope to provide the following services hole are drastically reduced, and thus the operator’s Hidalgo C-13 oil producer and deliverables: reduces the potential to the successful well. Zonal isolation was achieved using • Decision tree/flow chart and risk retrieval of pull-to-release devices. two 3 ½-in. open/close flow control analysis (DRA) for the workover valves and one 3 ½-in. variable flow The Rocky Point Field is located six operation (completion retrieval control valve with annular isolation miles northwest of Point Conception, off- options and risks). by using 7-in. feed through, multi-port shore California. Geologically, it consists packers with cut-to-release mechanisms. • Preparation of workover procedures of a series of complexly faulted anti- Monitoring of the respective zones was (retrieval and completion re-run, clines, which tend northwest-southeast. achieved in the upper two zones with including fishing operation contin- The reservoir is normally pressurized two dual gauge carriers with one quartz gencies). with oil-bearing, highly fractured inter- gauge reading annular conditions, and, vals. These formations are complex in the lower zone, a single gauge carrier • Identify and locate/source third- lithologically with calcareous-siliceous with a single quartz annular gauge. party retrieval service equipment. and clayey-siliceous lenses. 5/ • Determine potential re-usability Wells were cased with 9 8-in. 43.5-lb Permeability is largely derived from of equipment to be retrieved and casing to an approximate depth of 19,422 natural fractures, with little effective establish equipment requirements ft MD. The 7-in. liner was hung off with a contribution from the matrix rock. The for each re-completion scenario. reservoir is underlain by a large infinite liner top packer. acting aquifer providing sustained pres- • Plan for equipment redress logis- A tapered 4 ½-in. to 3 ½-in. produc- tics. sure support; water/oil contact varies tion tubing string was run to maintain between fault blocks. strength of completion whilst allowing • Prepare schedules for equipment The development plan for Rocky Point for optimal gas lift efficiency. 4 ½-in. tub- sourcing, reworking, redressing. 5/ included drilling eight deviated wells ing was run to the 9 8-in. above the liner • To assist in the re-completion design from the Hidalgo, Harvest and Hermosa with 3 ½-in. below. and in the secondary work scope platforms (Gary P. Hertfelder et al, 2007). (production analysis), a review of The main objectives of installing “intel- WORKOVER SCOPE well construction data required ligent completions” (“IC”) in these devi- The objectives of the workover were: (includes directional survey, open ated wells were to minimize intervention hole logs, drilling tour sheets, casing 1. Pulling the existing completion. whilst maintaining the ability to control tallies, casing ancillary equipment water production and maximize the pro- 2. Surveying the wellbore to determine list, cement bond logs, cement vol- duction from each of up to four zones. the source of the water production. ume logs, cement job reports). Other well objectives were: 3. Implementing a plan to address and b) The production analysis scope to gen- • Provide economic commingled produc- achieve zonal isolation between pro- erate: tion from up to four oil zones driven duction zones. • Analysis of available production by strong water drive allied to the 4. Re-completing as required. data from C13. constraints of topside infrastructure in • Compare C13 production data pre- highly fractured sandstone. To understand completely the impact and post-acid stimulation. • Maintain simplicity of installation and of any engineering and workover plan- operation. ning, a separate production analysis was • Prepare diagnostic plots and per- conducted to gather and analyze data form a diagnostic analysis. • Reliable design to afford required lon- to determine the potential source of the • Evaluate intervention options to gevity and minimize total life of well water influx. costs. shut-off water production (through- tubing or confirm the necessity for a • Maximize recovery from highly frac- This data may deliver an alternate solu- workover). tured strong water drive reservoir. tion to pulling the existing completion or assist in planning likely scenario of • Maximize early production. • Perform DRA on success and poten- re-completion equipment configurations. tial costs of treatment vs re-comple- • Minimize potential for early water Possible solutions could involve pumping tion. breakthrough. treatments, which would be evaluated in terms of cost and risk compared with