The Effectiveness of In-Situ Combustion is Proven For Shale Oil Production in Oman
The method for this type of UVS has been adapted and experimentally tested at the Kazan Federal University.
For the first time, the efficiency of oil shale development in the low-permeability reservoirs of the Natih B field in Oman has been proven. For this, the method of in-situ combustion was used.
The studies were carried out by scientists from Kazan Federal University, Sultan Qaboos University and specialists from the oil company Daleel Petroleum from Oman. The Devon news agency learned about this from a message from the press service of the NCMU “Rational development of the planet’s liquid hydrocarbon reserves” at KFU.
Oil shale and shale oil resources in the world are estimated at 650 trillion. tons. This is significantly more than the proven reserves of conventional oil. Oil shales are one of the types of sedimentary rocks rich in organic matter. They consist of organic chemical compounds (kerogen and bitumen) and inorganic substances.
Oil shale has a low bitumen content. And solid kerogen is the main organic matter from which liquid hydrocarbons can be obtained.
“Traditional methods used to extract light (low-viscosity) oil cannot be used to extract oil shale,” said Mikhail Varfolomeev, head of the department for the development and operation of hard-to-recover hydrocarbon deposits at the Institute of Geology and Oil and Gas Technologies of KFU.
The main difficulty lies in low productivity and high costs for the extraction of raw materials. This necessitates the development of efficient, environmentally friendly and economical technologies for the extraction and processing of oil shale.
“The new technology includes the stage of hydraulic fracturing followed by in situ combustion,” added Varfolomeev. “Its efficiency is increased by adding a catalyst proposed by the Kazan Federal University. In addition, catalysts can increase the efficiency of synthetic oil generation.”
Physical modeling of the in situ combustion process was carried out on a facility created in KFU – a combustion tube. A systematic analysis of changes in the temperature profile, pressure drop, and gases released during combustion has been carried out. Computed microtomography of the samples was also carried out for visual control of changes in the structure of the pore space during the experiment.
“In the course of in-situ combustion, a threefold increase in the permeability of the porous medium model and a steady propagation of the combustion front were observed,” said Alexander Bolotov, senior researcher at the Research Laboratory for Enhanced Oil Recovery Methods at the NCMU.
“This confirms the possibility of using in-situ combustion for the development of low-permeability oil shale and in-situ conversion of oil shale to produce synthetic oil,” added Ilgiz Minkhanov, junior researcher at the Research Laboratory for Enhanced Oil Recovery Methods at the National Center for Oil and Gas.
The oil and gas industry is already aware of the idea of in situ combustion for the development and processing of oil shale. Due to the low permeability of oil shale, hydraulic fracturing (HF) is usually required prior to air injection. One of the biggest questions is whether a fire front can establish and sustainably propagate in a low permeability zone that is not engulfed by fractures.
The study of Kazan specialists together with specialists from Oman was the first experimental work that confirmed this hypothesis. Catalysts have also been shown to increase the efficiency of this process.
