PJSC Gazprom Neft said it recently conducted five multistage fracing operations in the eastern part of Orenburg oil and gas-condensate field in southwestern Russia (OGJ Online, Oct. 4, 2013).
The company did not divulge production numbers or horizontal lengths, but said a combination of technologies led to a 50% increase in flow rates.
Gazprom Neft is using a viscoelastic diverting acid (VDA) to cause “an extreme network of fissures to develop” and allow additional inflow of oil into a well.
The acid can form a gel that temporarily blocks cracks and directs the remaining acid to other parts of the strata, increasing the coverage area. After interacting with hydrocarbons, the viscosity of the gel is reduced and “washed away” with the oil into the well.
The company is using VDA throughout the entire horizontal well shaft, not just in the fraced zone, along with “specialist” drilling mud.
Separately, Gazprom Neft also said production drilling is expected to begin in 2017 in Maloyuganskoye field in the Khanty-Mansiysk region in western Siberia. The company confirmed oil production there after formation testing in the Jurassic strata yielded an average of 11 tonnes/day from each of three “prospecting” wells.
Production drilling will start after geological data is analyzed and completion of geophysical and hydrodynamic work.
