Well-drilling services

Tender description

Directional drilling services, and rental of associated items, for drilling a deep geothermal well at the Eden Project, Cornwall, UK. Drilling will be almost solely in granite; tenderers should be able to demonstrate their ability to directionally drill in granite or similar crystalline rock, with an emphasis on drilling in hot wells. Directional drilling services and associated rental items for drilling a deep geothermal well in granite. Drilling will be in four sections: 1) Section 1:26" hole to +/- 300 m MD (vertical): The 26" hole section will comprise 5 1/2" 24.7 lbs./ft. premium class drill pipe in S135. The BHA for this section of the hole will consist of: — a downhole drilling motor (based on experience from a previous well in this formation; MWD for verticality), MWD telemetry and non-magnetic drill collar, — a 9 1/2" float sub with float, — 24” (23 3/4”) stabiliser, — 9 1/2" shock tool, — 9 1/2" drill collars, — 8” drill collars, — 5 1/2" HWDP, — cross-overs and subs as required. 2) Section 2:17 1/2" hole to 1 500 m MD (vertical): The 17 1/2" hole section will require 5 1/2" 24.7 lbs./ft. premium class drill pipe in S135. The BHA for this section of hole will consist of: — a downhole drilling motor, MWD (directional assembly) and non-magnetic drill collar, — a (8”) 8 1/4" float sub with float, — (8”) 8 1/4" shock tool, — (8”) 8 1/4" drill collars, — (8”) 8 1/4” drilling jar, — 6 1/2” drill collars, — 1/2" HWDP, — 16 3/4" stabiliser or stab ring, — cross-overs and subs as required. According to availability and spares, the 9 1/2" drill collars and the shock tool may be used too in this section as long as suitable stabilizers can be located in the correct size. 3) Section 3: 12 1/4" hole to 4 000 m MD (directional, about 3 870 m TVD): The 12 1/4" hole section will require 5 1/2" 24.7 lbs./ft. premium class drill pipe in S135. The BHA for this section of the hole will consist of: — a downhole drilling motor, MWD (directional assembly) and non-magnetic drill collar, — a (8”) 8 1/4" float sub with float, — (8”) 8 1/4" drill collars, — (8”) 8 1/4” drilling jar, — 5 1/2" HWDP, — at a minimum one 12” stabiliser or stab-ring, — cross-overs and subs as required. 4) Section 4: 8 1/2" hole to max. 5 260 m MD (about 4 880 m TVD): The 8 1/2" hole section will require a combination of 5" 19.5 lbs./ft. and 5 1/2" 24.7 lbs./ft. drill pipe in S135. Inside the 8 1/2” hole we recommend to use only 5” DP in order to allow for sufficient clearance around the tool joints. The up drag in the well will most likely be in the order of 30 to 50 tons by 5 000 m. The BHA for this section of the hole will consist of: — a downhole drilling motor, MWD (directional assembly) and non-magnetic drill collar, — a 6 ¾” (6 5/8”) float sub with float, — 6 1/2" drill collars, — 6 1/2" drilling jar, — 8" stabilisers, — 5" HWDP, — cross-overs and subs as required. If drag and torque become a problem in the lower intervals, the 6 1/2" drill collars will be reduced accordingly and the drilling weight will be compensated with additional 5" HWDP. The tenderer is expected to supply all equipment, material and personnel as laid out in full in the ITT documents available from EGL.