Touchstone Exploration Inc., Calgary, plans to drill two more wells in the Ortoire block onshore Trinidad and Tobago following testing of the Cascadura-1 exploration well.
The sidetrack, Cascadura-1ST1, was drilled to a total depth of 6,350 ft. Cased hole wireline logs and drilling samples indicated 1,037 ft of prospective hydrocarbon pay in the Cruse and Herrera formations at depths between 1,030-6,350 ft. Production testing was performed in two stages.
First stage
The first stage of the production test evaluated the lowest 162 ft of prospective pay in Herrera Gr7c and Herrera Gr7a formations between 6,056-6,218 ft. The second stage evaluated 345 ft of prospective pay between 5,570-5,915 ft in Herrera Gr7bc.
The first interval of the well was completed Jan. 17. Natural gas production testing commenced Feb. 4 with flow tests spanning a total of 44.5 hours, comprised of an initial clean-up flow period followed by an initial shut-in period and a four-step rate test, including a final flow test which extended to a total of 24 hours.
The test achieved peak production rate in excess of 5,735 boe/d (12% liquids) during the extended 24-hr test period, which included 30.1 MMcfd natural gas and 710 b/d natural gas liquids at 3,305 psi flowing pressure through a 40/64-in. choke. During the final 24-hour extended flow period, average rate was over 5,157 boe/d (13% liquids), including 26.8 MMcfd natural gas, and estimated 691 b/d natural gas liquids at 3,296 psi flowing pressure through a 40/64-in. choke. Drawdown was estimated at 20%. A total 39.4 MMcf of gas (6,570 boe) produced during the test, with 959 bbl natural gas liquids and 41 bbl water. The extended flow test yielded 55° API natural gas liquids at a ratio of 26 bbl natural gas liquids per MMcf of natural gas produced. Laboratory analysis indicated liquids rich natural gas with no hydrogen sulfide.
Following the extended flow test the well was shut in for 20 days for pressure build-up survey. Based on shut-in data, the stage one completion was capable of 99.3 MMcfd absolute open flow.
Second stage
The second interval of the well completed on Mar. 6, and the second stage flow test commenced on Mar. 8 following the same time and testing parameters as stage one. The test achieved peak production rate in excess of 5,760 boe/d (15% liquids) during the extended 24-hour flow test period. This rate included 29.4 MMcfd natural gas and 865 b/d natural gas liquids at 3581 psi flowing pressure through a 40/64-in. choke. During the final 24-hour extended flow period, average rate was in excess of 5,472 boe/d (14% liquids), including 28.1 MMcfd natural gas and 783 b/d natural gas liquids at 3578 psi flowing pressure through a 40/64-in. choke. Drawdown was estimated at 13%. A total 43 MMcf of natural gas (7,162 boe) produced during the test, with 1,095 bbl natural gas liquids and 78 bbl water which included 69 bbl load fluid. The extended flow test yielded 55° API natural gas liquids at a ratio of 28 bbl natural gas liquids per MMcf of natural gas produced. Laboratory analysis indicated liquids rich natural gas with no hydrogen sulfide and no measurable solids.
Stage two flow testing supports an initial production range of 7,750-9,700 boe/d, including an estimated 40-50 MMcfd of natural gas and an estimated 1,100-1,400 b/d of natural gas liquids, exceeding pre-drill expectations, the company said. The well is shut-in for an extended pressure build-up survey after which pressure data and geophysical mapping will be reviewed to define resource potential.
Additional drilling
Coho-1 is expected to be drilled and on-line by early in this year’s third quarter. The pipeline required to tie-in the dry gas discovery has been surveyed and is currently awaiting local construction contract bids. The pipeline has been specified up to 20 MMcfd for production from Coho-1 and potential future locations.
The company expects to spud Chinhook-1 in the middle of the year’s second quarter. Construction of the surface location and access road for the prospect is close to completion. The well lies about 1 km south of Cascadura-1ST1 and is targeting hydrocarbons from the same horizon encountered in both the Coho and Cascadura discoveries in a new and unique fault block.
Touchstone Exploration is operator in the Ortoire exploration block (80%) with partner Heritage Petroleum Co. Ltd. (20%).
