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DNO schedules Yemen production tests next year

Uchenna Izundu
International Editor

LONDON, Dec. 29 -- Norway's DNO ASA will start another round of production tests early next year in Yemen from the Tasour No. 23ST exploration well on Block 32 after having initial overheating problems with a large electrical submersible pump.

The Tasour No. 23ST exploration well was drilled to 3,139 m TD and suspended as a potential upper Naifa oil well. The well targeted prospects in the Naifa carbonates and fractured basement. DNO said that it had recovered 200 b/d of 27ยบ gravity oil and 457 b/d of water from a 10.5 m perforated interval in the upper Naifa carbonate.

Oil from the production tests will be treated at the Tasour plant and exported.

The well had drilling problems at 2,586 m and it was subsequently plugged back to 852 m. DNO said it drilled a sidetrack well to a TD of 3,139 m (about 300 m into the basement).

"Testing was carried out on the basement and on two separate Naifa carbonate zones. No hydrocarbons were recovered from tests on the basement and the lower Naifa carbonate," DNO said.

DNO has an interest of 38.95 % in Block 32; partners are Ansan Wikfs 42.9%, TT Holding 13.12%, and Yemen Co. 5%.

Early next year, DNO will drill an exploration prospect with Naifa carbonates on Block 43 and plans to drill its Nasim No. 1 exploration well on Block 72. Nasim No. 1 will test prospects in the Qishn sandstones and in the Naifa carbonates.

On Block 53, DNO is testing its Hekma-1 well, which was drilled to a TD of 3,715 m in the basement. During the second test, oil flowed at a rate of 800 b/d from Kholan sandstone (3,186-99 m MD) through 7-in. liner immediately above the basement.

"Two additional tests are planned in the well; one combined tests of two Madbi sandstone intervals (3,022-30 m and 3,001-13 m), both interpreted as oil-bearing from wire line logs, and one test in the Madbi carbonate (2,919-30 m), which yielded good hydrocarbon shows while drilling," DNO said.

On Block 53, DNO has suspended its Bayoot South No. 1 well, drilled at a TD of 3,106 m immediately south of Bayoot SW-1 and SW-2 to test a Madbi fan down-flank of the basement high. DNO added: "When drilling 8-1/2-in. hole to TD, the well started to flow oil, and heavy mud was needed to control the well. The well is now suspended awaiting supply of equipment to continue drilling and testing."

The rig utilized to drill Bayoot South No. 1 will now be moved north to drill Balal No. 1, a Qishn prospect northeast of Sharyoof field.

The Bayoot and Hekma structures are both located on a prospective basement-Madbi trend between Sunah field on Block 14 some 14 km to the southeast, and Kharir field on Block 10 some 15 km to the southwest. The Sunah and Kharir fields have proven to be the most successful basement producing fields in Yemen to date, DNO added.

DNO is confident about the southern part of Block 53 following its drilling results. "Out of four recent wells drilled within this area, three wells have proven oil. Although tests to date have not yielded production rates at levels achieved from the shallower Qishn sandstones, higher production rates could be achieved through other drilling, completion and stimulation techniques," DNO said.

Contact Uchenna Izundu at uchennai@pennwell.com.


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