IS THIS ANOTHER RECORD FOR MARRIOTT DRILLING?
Marriott Drilling Group
Always striving to meet our clients objectives, with focus on well integrity and value for money
Marriott Drilling (Marriott) has recently successfully completed the drilling of a conductor for a very deep exploration well in Albania. Shell Upstream Albania (Shell) is continuing their appraisal of the Shpirag fractured carbonate reservoir. Marriott was engaged to carry out the construction of the conductor ahead of the main drilling.
The challenge was to drill a large diameter conductor through an Eocene karst sequence with the water table at some 100 m below ground. Marriott opted to drill the main part of the initial entry through the karst limestone with a down-the-hole-hammer (DTH) to avoid aquifer contamination and any interference by losses using fluid circulation affecting local water wells.
Marriott mobilised a Liebherr LB20-230 universal drilling machine from the UK together with a Robit Hyper 241 DTH, an 18 in shock absorber and a 914 casing system allowing the casing to be drilled as the hole is advanced.
The initial conductor was drilled at 48 in diameter to 32 m and a 42 in casing was set and cemented to surface. This was followed by the Robit DTH and ring bit system to drill from 32 m to 113 m at 40 in diameter followed by the installation of a 36 in casing, which was also cemented back to surface. Drilling in 40 in diameter to 113 m with a DTH is believed to be a world record.
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Now below the water table, the conductor was with the DTH to 115 m and a string of 30 in casing was installed and cemented to back surface.?The conductor borehole was then continued by flooded reverse circulation to 154?m in 28 in diameter followed by a cementing operation to squeeze cement into the formation and karst zones and fill to well back to 115 m to stabilise the initial entry into the well. This interval will be drilled out by the main drilling contractor.
A few facts. A total of 245 ton of cement was pumped and 714 m of weld used across the 42 in, 36 in and 30 in casings. The inclination of the conductor at 115 m was 0.10o equivalent to 370 mm offset in a 40 in hole that was drilled without directional control.
This was another outstanding performance by the Marriott team.
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2 年Iam welder?
Mécanicien industriel Domtar CNP72400
2 年Multidisciplinary hydraulic mechanic looking for a job
Well Delivery Manager at Brunei Shell Petroleum
2 年The Marriott team did a fantastic job - great technical solution and an incredibly professional team.
Profesional en Ingeniería Petrolera con gran adaptabilidad y capacidad al cambio moderno.
2 年The best!!!
C Suite Executive with 20 years experience working in various parts of Africa and the Middle East
2 年Well done Team Marriott - again showing how a dedicated set of professionals working together - both amongst themselves and with their Client - can achieve results that set the bar for other Drilling Companies.