ExxonMobil drills record extended-reach well at Sakhalin-1
ExxonMobil Corp. has surpassed its own world record for reaching offshore deposits with land-based extended-reach technology, drilling from an onshore well at its Sakhalin-1 project in eastern Russian to a target area 7 miles offshore.
The project team at Sakhalin-1, which is operated by the company’s Russian subsidiary Exxon Neftegas Ltd., used what ExxonMobil calls “leading-edge technologies” to drill the record Z-12 well in half the time needed by conventional technology.
The Z-12 well was drilled to Chayvo field, which contains 17 of the world’s 30 longest extended-reach-drilling wells, and set a record by achieving a measured depth of 11,680 m.
The record exceeds by 398 m the prior world record set in 2007 by Exxon Neftegas’s Z-11 well, also at the Sakhalin-1 project.
The process has been beneficial in terms of production and environmental safety, according to Morris Foster, president, ExxonMobil Production Co.
“This drilling success has contributed to other Sakhalin-1 project achievements, including the commencement of production 5 years after the project was declared commercial and 100 marine tanker shipments in the first year of export operations,” said Foster.
“Employing extended-reach technology to drill onshore beneath the seafloor to offshore oil and gas deposits eliminates the need for additional offshore structures, pipelines, and associated activities.”
The 22-story Yastreb drilling rig, which anchors the Chavyo well site on Sakhalin’s northeast coast, was designed to drill extra-long extended-reach wells nearly 11 km offshore. Photo from ExxonMobil.
ExxonMobil said its “Integrated Hole Quality” technology was used to manage a broad range of well variables, including rock strength and stresses and well-bore hydraulics. It also managed the Fast Drill optimization process that analyzes the amount of energy used to make the drilling process faster and more efficient.
The firm’s announcement coincided with reports that OAO Gazprom plans to sign an agreement in April or May to buy all natural gas produced at the Sakhalin-1 project.
“We hope that in April-May we will be able to sign a binding agreement with Exxon to buy 11 billion cu m[/year] of gas,” said Gazprom’s Deputy CEO Alexander Ananenkov at a meeting on the development of the Far East chaired by Russia’s First Deputy Prime Minister Dmitry Medvedev.
According to Ananenkov, gas reserves of Sakhalin-1 fields total 500 billion cu m, and annual production is expected to reach 11 billion cu m.
He said the gas would be supplied to consumers in the far eastern regions of Russia, as well as the Far East, where demand is expected to reach 25 billion cu m/year by 2020.
According to the consortium partners, Sakhalin-1 comprises the Chayvo, Odoptu, and Arkutun-Dagi field blocks, which contain potential reserves of about 2.3 billion bbl of oil and 485 billion cu m of gas.
Exxon Neftegas, holding 30% interest, is operator for the Sakhalin-1 group. Partners include Japan’s Sakhalin Oil & Gas Development Co. Ltd. 30%; RN-Astra 8.5% and Sakhalinmorneftegas-Shelf 11.5%, both affiliates of Russia’s Rosneft; and India’s ONGC Videsh Ltd. 20%.