Quad multilateral well completed offshore Abu Dhabi

Offshore staff

(Middle East) - Zakum Development Co. (ZADCO), has successfully drilled and completed the first offshore quad lateral multilateral system utilizing multiple completion windows in a deviated well in the Upper Zakum field.

ZADCO worked in conjunction with ADMA-OPCO (Abu Dhabi Marine Operating Co.), ADNOC (Abu Dhabi National Oil Co.), JODCO (Japan Oil Development Co. Ltd.) and JOGMEC-TRC (Japan Oil, Gas and Metals National Corp. - Technology and Research Center).

This was also the first time three laterals in the same well were accessed and stimulated using mechanically selective through-tubing re-entry equipment.

The wells in the Upper Zakum field require the ability to selectively re-enter laterals to effectively stimulate the entire length of each lateral as well as provide the ability to obtain future data acquisition in the laterals.

Halliburton's Sperry Drilling Services LatchRite pre-milled window multilateral systems and IsoRite isolated multilateral completion system were used for this completion.

The well construction was completed in two steps: the drilling and completion operations were done with a drilling rig, followed by the stimulation and production testing operations using a work-over barge.

This well represents many firsts, according to the involved companies.

The most important achievement was the construction of a multiple window multilateral well after remedial cementing operations were performed to restore zonal isolation around the liner.

The well is the first deviated, multiple IsoRite system window application in the UAE and the highest angle - 89°ree - at which the dual, mechanical through-tubing re-entry tools have been run successfully in the world.

This was the third successful and most challenging trial well done in the Upper Zakum field to date.

The Upper Zakum reservoir consists of several layers of oil-producing formations and each formation must be isolated from the others.

The well accessed four separate reservoir targets from one main wellbore.

The well is being produced through dual tubing strings, with the three lower reservoirs producing through one string and the upper-most reservoir producing through the other tubing string.

02/09/06