Liner

*LinerLinersAny string of casing whose top is located below the surface, hung inside the previous casing and is run to its setting depth by drill pipe.LINERHANGER CASINGSHOE OVERLAP 50 - 500 FT

*LinerWhy Liners ?Prime reason:Save $$(Cost of 1 Joint of Casing can be $3,000!)Cover Corroded/Damaged CasingCover:Lost Circulation Zones.Shales or Plastic FormationsSalt ZonesDeep Wells:Rig Unable to Lift Long String of Casing.

*LinerTypes of LinersProduction:Most commonSave $$Slotted linerIntermediate/drilling:Cover problem zone in order to be able to continue drillingTie-back/liner complement:From top of existing liner to surface, or further up casing to cover corroded or damaged zone.

*LinerTie-Back (Liner Complement)The integration of the liner with casing run to surface

*LinerTie-Back (Liner Complement)The integration of the liner with casing run to surface

*LinerTie-Back (Liner Complement)The integration of the liner with casing run to surface This is often done if production is commercially viable or there is damage to casing above the liner TIE BACKSTINGER WITHSEALSLINER

*LinerHardware DP Wiper Plug Liner or Dart Hanger

Landing Collar/Plate Casing Shoe

*LinerHardware Running Tool

*LinerProcedure for Setting LinerRIH with drillpipeAt liner hanger depth, condition mud(Reciprocation / Rotation)Release slips (liner hanger)(Rotation - mechanical pressure - hydraulic)Set slips, release liner weight, check to see if running tool is freePump mud - to ensure free circulation Cement / Displace / Bump plug / Bleed offRelease setting toolPOOH above TOC and circulateNOTE: A liner swivel can be run below the hanger to ensure that the tool can be rotated even if the liner is stuck or set.

*LinerAnimation

*LinerJob Procedure LinerPressure test lines.Pump wash/spacer.Pump slurry.Drop "Pump Down" plug (or drill pipe wiper dart).DisplaceTo running toolShear "Wiper PlugDisplace to Float CollarBump plug/check for returns.Release tool.Pull up to T.O.C. and circulate.

*LinerLiner OverlapCementing the liner lap is critical .Too much cement above the liner hanger is not recommendedSo make sure that uncontaminated cement is present at the liner lap - washes and spacers / WELLCLEAN IIIf not, there is communication from the annulus to the formation

*LinerRecommendations for Liner CementingEnsure rheology of cement system is adequate for 100% mud removal Turbulent flow, if possibleConsider 5 - 10 min. contact time at liner lapBatch mix cementMinimize U-tubing effectRotation of liner during cementing (special bearing in tool)Adequate mud conditioning prior to cementing

*LinerExample Calculation - LinerWell Information:9-5/8" 47 lb/ft intermediate casing from surface to 6500 feet7" 29 lb/ft intermediate liner from 6200 ft to 10,500 feet6" open hole to TD at 14,500 feetDrill pipe 3-1/2" 13.30 lb/ft4-1/2" 16.60 lb/ft liner required from 14,400 ft to 400 ft inside 7" liner.Float collar 80 feet above shoe.Cement required to top of liner with 20% excess in open holeCalculate:Slurry Volume and Displacement

*LinerProduction Liner Cementing Job3 1/2 drill pipe 13.3 lb/ft 9 5/8 casing shoe at 6500 ft7 liner 29 lb/ft Top at 6200 ft9 5/8 casing 47 lb/ft7 liner shoe at 10500 ft 6 Open hole + 20% Excess4 1/2 liner 16.6 lb/ft top at 10100ftCollar at 14320 ft 4 1/2 liner shoe at 14400 ft

*LinerLiner Example Calculations - ResultsSlurry Volume:Volume #1:0.0981 ft3/ft x 400 ft = 39.2 ft3Volume #2:0.0859 ft3/ft x 3900 ft x 1.20 = 402 ft3Volume #3:0.0769 ft3/ft x 80 ft = 6.2 ft3Total Volume: 447.4 ft3Displacement:Drill Pipe:0.00742 bbl/ft x 10,100 ft = 74.9 bblsLiner:0.0137 bbl/ft x 4220 ft = 57.8 bblsTotal Displacement = 132.7 bblsMax. overdisplacement = (80 x 0.0137) / 2 = 0.55 bbls

*LinerConclusionLiners have many applicationsThe main feature is that normally you have small volumes of slurry and high pressures during the job.Liner overlap is the most critical part to cement correctlyEven though most of the times we are not at charge of the hardware (liner hanger, cement head, etc.), we must have knowledge of what has been run in the hole, and the way it works.It is important to slow down the displacement to avoid excessive pressures (shear pins, end of displacement)

*LinerCase Study* Mark of SchlumbergerNorth Africa

What is a Liner?Any string of casing whose top is located below the surface. Set by drill pipe,which is subsequently retrieved. Why run Liners? (Ask class to give opinions and list them)1. $$ Save Money. Most commonly used to save money.2. To Fix Broken Casing3. To Cover Problem Zones4. Deep Wells: Unable to lift long casing stringTypes of Liners1. Production - To cover production zone. Includes slotted liners.2. Intermediate/Drilling - To cover problem zones.3. Tie Back/Liner Complement - Run Liner Back to surface due to corrosion or pressure problems.Explain Functioning of the Tie Back Liner. Original Liner has to be pre-disposed to receive tie back - usually has a polished seal bore attached to the top of the liner hanger. A stinger with seals is run on the end of the tieback casing or liner. In some special cases, cement can be pumped down the tieback and up between the tieback and previous casing, just before landing the seal sub.HardwareLiner hangerThe liner hanger is run into the hole with a running toolIn case of a future lie back liner the top of it will be differentCasing shoeWiper Plug (optional)Wiper Plug / DartIt is call Drill Pipe Wiper Dart, Wiper Plug, Pump Down PlugSometimes are used one or two, depends of the landing collar or landing plate used.Landing collar or landing plate

Note: Check animation of slide. It shows liner hanger and slipsImportant: Slips must be set prior to cementing and the running tool must be free from the liner. Some major incidents have occurred where the running was not released prior to cementing and it was found that the running tool was stuck in the liner hanger - but after cement had been pumped and put in place.Show procedure for setting Liner.Must note that running and setting liners is not our business - we do need to understand what is involved but should not get involved.Usually 50 m to 100 m of cement is used as excess above the liner hanger - this varies from oil company to another. This cement should be left in place - it can be easily drilled out once set.When reverse circulating after bumping the plug, take care not to exceed fracture pressures. If the margin is very low, prefer to circulate directly, ie. down the drill pipe.In some cases a liner packer may be run together with the liner. Care should be then taken to avoid over pressuring this area which could lead to setting the packer.Always check with the liner hanger people (Weatherford, Halliburton, Brown, etc.) what is the maximum rate and pressure that we can circulate past the liner hanger. Ideally, this should be done at the design stage, but we must check before the job. Review Job Procedure (Ask participants to make job procedure).

See overhead.

Note: Circulation after releasing tool is recommended.Cementing a LinerThe most critical part is Liner overlap. How long should it be? This depends on purpose of Liner: 50 - > 500 ft. (Production Liners are usually more to ensure good seal). Note that you should not pump too much cement above top of liner (Normal = 50 -150') Explain possible problems of poor cement. For this reason Liners are considered more critical and spacers/washers are normal. Some more important issues to bring up are communication between the top of the liner and the zone just under the previous casing shoe - leading to unwanted production up into the annulus of a future production string; another problem is that if zonal isolation is poor, it is very hard to squeeze off this zone;the volumes of the liner lap are typical very small - 10 bbls or less usually and can be easily contaminated.Note that the CBL should not be considered for checking the quality of the cement job across the liner lap due to there being concentric casings with the CBL being influenced by the previous casing.Show 'Recommendations for Liner Cementing'. Usual good cementing practices are sufficient.Batch mix is very important due to fact that mixing 'on the fly' starts with low density cement that will end up at Liner overlap. Allow 15 mins. for calculations. Review answers on overheads Review answers on overheadsThird Party ResponsabilitiesSetting tool must be released prior to cement jobMaximum pressures must be checked prior to the job. (liner hanger, cement head from third partyCase historyCritical water zones in a North African field required isolation with an intermediate casing cemented in two stages. This operation increased rig time, cost and potential trouble for this casing operation. Because the stage tool created a potential future weakness in the intermediate casing string, the production casing had to be run to surface to cover the stage tool and protect it from future production operations.The casing program was redesigned using LiteCRETE technology to replace the two-stage intermediate casing with a single-stage casing requiring only one cement slurry. This saved stage-tool-running time, associated rig costs and eliminated the risk associated with a stage tool. Instead of a full production string, a production liner was then run back into the intermediate casing, saving additional time and expense in well construction.LiteCRETE technology offers a well-construction solution with low permeability and low density. Superior-quality cement columns can be pumped higher in the annulus so multiple-stage cementing becomes unnecessary.