Drill liner, cladding, liner hanger developed from casing expansion

Shell rolls out product in two joint ventures

William Furlow
Technology Editor

E2TECH is developing a short cladding application of expandable casing technology as a step toward its concept of the mono-diameter well design. [17,988 bytes]

To develop and market the expandable casing technology, Shell Development Technology has formed two joint venture companies. Enventure is a 50-50 partnership with Halliburton Energy Services to further develop the technology and market it in the US and Gulf of Mexico. E2TECH is a 50-50 company Shell formed with Baker Hughes for the same purpose focusing on the North Sea and international markets.

Both companies have exclusive license to the technology for the prescribed markets for three years. At that time, the markets will open up and the two companies will be expected to compete head-to-head. Richard Haut, formerly of Halliburton Energy Services (HES), is general manager of Enventure. He said he and Lance Cook, formerly of Shell Development Technology, run the company and answer to a six-member board of directors. Three board members are from HES and three are from Shell.

Drill liner system

The company is focusing efforts on further development and commercialization of the basic patents and technology licensed by Shell. These efforts began in July, 1998. Shell and Halliburton engineers and scientists met to develop a field-ready system. Their work followed two basic product lines. The first will be a drill liner system for extending casing shoes. This application should find a good market in deepwater fields where the fracture gradient and pore pressure make for narrow drilling margins.

The driller can expand the casing once downhole, nearly matching the internal diameter (ID) of the previous strings. This allows the driller to set the casing shoe at an extended depth. The 13 3/8 in. expandable casing system can run inside 16-in. casing to extend the 16-in. casing shoe. The 13 3/8-in. liner can be expanded to an outside diameter (OD) greater than 15 in. giving it a 14 1/4-in. drift. This allows the driller to drill down and set a standard 13 3/8-in. casing string at a deeper depth.

A prototype of this system is currently ready for field trials and should be fully commercialized by the summer of 1999.

Cladding, liner hanger

The second product line under development is a 3.5-in. by 5-in. cladding system. This product would allow operators to clad off corroded lengths of casing so that a well could be re-entered and extended. The cladding system clads off the bad pipe to regain integrity in the wellbore. Enventure will perform a field trial of this system in early April.

A third innovative product Enventure is working on is a liner hanging system, a prototype of which will be ready for testing by June. Using the expandable tubular system technology over a very short section will simplify existing liner hangers. This provides a hydraulic pack-off seal as well as acting as a liner hanger.

The original goal of the expandable casing technology was to develop a drill liner system for deepwater applications. One of the current limitations for ultra-deepwater exploration is that the program runs out of casing strings, giving the well a bottom hole ID too small to produce from. As Shell worked on this technology researchers found some spin offs products, although the core goal is still extending drilling capabilities in deepwater.

Bennett Richard, E2TECH's managing director, said this company is taking a stepwise approach to the development and introduction of expandable casing products. Ultimately, he said the technology would allow for the creation of a mono-diameter well design.

As the name implies, this would be a well without the traditional telescoping of casing strings down to total depth. Instead the mono-diameter design would use one size of casing, lowered into the hole then expanded in situ. This "nesting" of the casing strings means the entire wellbore will have a consistent diameter.

Other advantages are the additional pipe handling capabilities and storage capacity of rigs, which are dealing with one size of casing. This, of course, will mean a larger tubing size through the production zone and faster drilling because there won't be any need for handling large diameter initial casing strings. The only diameter limitation of each casing string is the thickness of the steel. This means more liners can be set to mitigate well stability and inflow problems.

To reach this ultimate goal, E2TECH will follow a similar path as that announced by Enventure. The first product will be a short-length clad liner, followed by a longer clad application. E2TECH is also working on a slotted expandable casing product for zonal stability applications.

Reducing costs

Overall, expandable casing technology will reduce the operator's costs, especially when the full potential of these products is realized. "In three to five years every well will want one," Haut believes. The casing is run downhole in its smaller size, and then a pig is driven through the tubular to expand it. In developing this technology, Enventure will have to address lubricity issues, pig wear, and the question of how long the pig can run before it wears out.

The companies were formed for 20 years, with a three-year incubation period, Halliburton has the US and Gulf of Mexico rights to market the technology, as well as existing Halliburton projects worldwide. On December 9 of 2001 Halliburton and Baker Hughes, in the guise of Enventure and E2TECH respectively, will go head to head across the globe.

Shell had two motivations for developing the technology. The company can apply it to Shell deepwater projects in the US and problems in the North Sea. If the two joint ventures develop similar or different technologies, Shell wins either way.