Driven by the need to boost oil reserves, Dubai Petroleum embarked on a new mission last year to drill and complete its first multistage, hydraulically fractured, and propped horizontal well from an offshore platform.
The government-owned oil company, which primarily operates offshore wells, reports that because the project targeted a tight unconventional carbonate formation with completion techniques used almost exclusively onshore, it may be the first of its kind for the offshore sector.
“We believe this will be part of the future for Dubai as an oil-producing country,” said Frederic Chemin, a general manger with Dubai Petroleum, who added, “because of the size of the reserves we will be working very hard on this.”
Chemin presented the details of the project at the 2016 SPE Annual Technology Conference and Exhibition recently held in Dubai. He noted that more information is needed to assess the resource potential of the newly tapped formation, a tight carbonate rock known as the Shilaif, but said the results from its first exploratory well could help multiply Dubai’s reserves “by quite a large volume.”
A study published last year by the US Energy Information Administration estimated that the Shilaif formation, which encompasses parts of Saudi Arabia, Oman, and Qatar, may hold 22 billion barrels of recoverable oil; though such preliminary figures are usually best taken with a grain of salt.
The eight-stage well was drilled last December as a sidetrack inside a producing offshore well located not far from the UAE’s maritime border with Iran. Due to logistics issues, the well was not completed until April.
Dubai Petroleum has not disclosed production rates but said the well’s hydraulically induced fractures were successfully propped, and that it is flowing oil with only a 3% water cut.
Chemin said the company took on its first unconventional project in the offshore arena because of its focus on increasing oil reserves; as the formation moves onshore it becomes primarily a gas play.
Describing the Shilaif as a “strange carbonate,” Chemin said one of the big challenges the engineers faced on the project was to prove that the formation was indeed an unconventional target. He explained that what makes the formation unique is that it is rich in organic matter, but has no dolomite or silica, two of the most common mineral features of other carbonates.
The formation also sits in between other producing layers, so hydrocarbon fingerprinting was used to confirm that the Shilaif is an oil-producing source rock.
Chemin said the company’s goal now is to bring down costs so it can economically develop the formation. “The different challenge for us is the offshore environment,” he said. “And so we’ll have to really be smart on this.”
