First horizontal wells commissioned at Gazprom Neft Orenburg’s Tsarichanskoye field
Gazprom Neft Orenburg, a subsidiary of Gazprom Neft, has put on-stream the first three horizontal wells at its Tsarichanskoye field. The total daily flow rate of the wells is 615 tons of oil, which exceeds initial target values.
After construction work at the wells was completed, multiple hydraulic fracturing was performed using proppant. The new wells are operated with artificial lift.
The operations at Tsarichanskoye field are unique because they involve horizontal drilling in the Devonian system that is known to be especially difficult to develop. Using horizontal wells with multiple frac jobs is one of the methods of bringing tight reserves into development. Drilling to a depth of 3,700 vertical meters makes it a very hard and technologically challenging field operation. This has never been done in the Orenburg region before. The length of the wells' horizontal sections is 600 meters.
Since the beginning of the year, ten wells have come on-stream at Tsarichanskoye field, seven of which are vertical with an average flow rate of 77 tons per day, in addition to the three horizontal wells. Gazprom Neft Orenburg will commission six more wells before the end of the year, four of which will be horizontal.
Tsarichanskoye field is the largest field to be discovered within Orenburg Oblast in recent years. It was discovered in 2005, and has been demarcated within the Tsarichanskoye subsoil area.
The development target at Tsarichanskoye field is the Devonian DKT formation. It consists of alternating layers of sandstone argillites and siltites and has low permeability. Hydraulic fracturing is necessary in order to obtain a hydrocarbon flow from this type of rock.
The Devonian System is an aggregate of ancient strata in the earth's crust that formed during the Devonian Period of the Paleozoic Era. The Devonian System is divided into Lower, Middle and Upper parts. Each part is further subdivided into two stages.
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