Reeled expandable casing creates single diameter well
A process of installing expandable reeled tubing to create cased hole with a single diameter from tophole to completion has been patented by Shell International Exploration & Production. The process would use tough, ductile steels, that can be expanded with a pig, or composites, which could be chemically expanded and thermally cured downhole. Expansion in both types would take place downhole after the tubing is installed.
The process has a number of benefits:
- Tophole can be drilled to 9-12 in. diameter, instead of 26-39 in.
- Removal of borehole material can be cut by 75%.
- More strings of production tubing can be accommodated downhole
- More diameter at TD for completion tools and gravel packs
- More diameter to cut windows or sections.
- Fewer bit changes to accommodate smaller diameters.
- Less mud in circulation with smaller tophole annulus.
- Easier casing repair.
- Reels and injectors require less weight on drill floor than conventional jointed pipe assembly.
- There are drawbacks to use of the process, however, which are being studied. The expansion process cannot be used on jointed pipe and requires uniform reeled segments. Steel coiled tubing has not been rolled in sizes greater than 4-1/2-in. diameter. Large sizes require a large number of reels, and can present larger loads than jointed pipe.
- Another minor drawback is a lack of understanding of the expansion pig process. At present, steel pigs with molded zirconium oxide ceramic material on the outside are being studied as a way to prolong the wear of the pig surface exposed to the expansion process.
- The use of composites for expandable casing and liners holds more promise than steel. The composites are lighter in weight and could be reeled on smaller spools. The composites are injected downhole and expanded with pressurized fluid and heat cured. The drawbacks on the use of composites is their cost and restriction to boreholes with temperatures under 100 degrees C.
Mass balance leak detection installed on Bonito complex
A system of flow computers that compare flows at various sections of the 72-mile Bonito pipeline in the US Gulf of Mexico can determine if a leak or volume loss has occurred anywhere along the line. This mass balance system was developed by ITT Barton of City of Industry, California.
The networked computers measure liquid volumes being transported through 18 platforms and the onshore terminus and determines variations. If the mass volumes do not match, an alarm sounds. The flow calculations are performed on one-meter and two-meter runs and reported every 60 seconds. The system can be varied to deal with a variety of differential pressures or flow meters.
Composite extended reach drillpipe step closer to development
The lateral distance for extended reach wells can surpass nine miles if composite drilling tubulars are used instead of steel. The prediction was made in a technical paper entitled "Extended Reach Composite Materials Drillpipe," (G. Hareland, W. Lyons, D. Baldwin, G. Briggs, R. Bratli), presented at the IADC/SPE conference in Amsterdam. Composite drillpipe has neutral buoyancy in 15.4 lb/gal drilling fluids, a very attractive feature, while steel pipe tends to sink to the bottom of the borehole. As a result, drillers are encountering severe drag and friction is attempting to surpass the 6-mile lateral limit. With composites, drillers experience applied torque values 5-15 times lower than for steel drillpipe.
Designers have successfully installed metal box and pin tool joints on composite pipes, a process which allows for joint handling by tongs. The pipe exterior also has built-up wear knots which act as protective stabilizers to prevent buckling and wall wear. Early tests have shown the wear knots are key to preventing rapid wear of the pipe OD.
High temperature flexible flowlines
High temperature well flows in the North Sea are pushing research into upgrading the capability of flexible flowlines used for risers on floating production units. Aberdeen-based MCS International, funded by Scottish Enterprise and assisted by Material Engineering Research Laboratories, wants to increase the flowline melting point limitation from 120 degrees C to 200 degrees C. The lab will evaluate new polymer materials for the internal pressure sheath of the pipe.
Methanol fuel source for energy cell
Methanol (methyl alcohol) is entering the competition to produce a fuel cell with the necessary low cost, power, longevity, and quick recharge capability. Methanol can be made from natural gas. The device was developed by the Jet Propulsion Laboratory and the University of California. Methanol and water are introduced to the fuel cell. A catalyst-coated membrane in the middle of the chamber separates the hydrogen atoms from the mix, creating a positive charge on the liquid side of the membrane and a negative charge on the gaseous side. The hydrogen-oxygen reaction process which involves and ion transfer through the membrane produces water and a small amount of carbon dioxide. As in most other similar processes, the catalyst is the key. Methanol is an excellent source of hydrogen. Pure hydrogen is dangerous to transport and difficult to use in re-fueling, and ethanol and methane do not work as efficiently as methanol.
Borehole stability software developed
A new program that can predict the stability of inclined boreholes over the life of the reservoir has been developed by the University of Oklahoma Rock Mechanics Institute (Norman, Oklahoma). In addition, the PBORE-3D software provides the most favorable orientation for drilling and production.
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