Oil & Gas
№ 7 (July 2006)
Getting Oil Easier Out of Hard-to-Recover Reserves
Russian science is frequently accused of being out of touch with reality and "lingering behind" rather than being a "vanguard of progress" in the oil and gas industry. Fortunately, statements about lack of demand for Russian
Recently developed technologies aimed at oil recovery enhancement and well stimulation have already been used successfully at fields owned by RITEK and other LUKOIL production units. In search of innovative solutions for difficult conditions of Western Siberia and Tatarstan, a breakthrough was made that brought the company to a new level of producing hard-to-lift reserves more effectively. Today, the demand for RITEK's technologies and services is growing both in Russia and abroad.
From West Siberia to Middle East
In Oman, field application of RITIN chemical has started since 2001. This chemical has been designed jointly by RITEK-Electrogorsk Scientific and Production Center (RITEK-ESPC) - one of RITEK's service units, and the Department of Inorganic and Colloidal Chemistry of Gubkin Oil and Gas State University. By applying RITIN polymeric-gel system, Petroleum Development of Oman Co. was able to reduce water cut, typical for local fields' wells at the current stage of development. Also, while RITIN's payback period with Russian producers ranges from one to three months, in Oman that supplies oil at world prices, it is reduced to a few weeks. The Middle East practice that allowed increasing oil influx by 30 percent made the product interesting to specialists from such countries as India and Venezuela.
RITEK-ESPC controls production of RITIN that has been organized at Elektrogorsk at a plant staffed with only 40 employees. This Moscow Region-based plant supplies oil producers with other chemicals as well. One of these products is POLYSIL. Together with RITIN, it became the company's "business card" in the enhanced recovery technlogies market. Due to particles' submicron dimensions, the modified POLYSIL silica, as organic suspension or emulsion, easily penetrate the pore space and change the rock's filtration parameters. Treatment of injection wells, which have terrigenous reservoir, with hydrophobic POLYSIL ensures considerable improvement of formation permeability, increasing bottomhole area's injectivity by 2.5-3.5 times.
In 1998, RITEK patented a polymeric composition, Plastik KS that became an alternative for cement and silicate materials - traditional casing sealants. "Unlike cement that is affected by acid, our material is resistant to aggressive media," says Viktor Tarabrin, chief geologist of RITEK-ESPC. "High degree of adhesion with metal and rock ensures high quality of operations." For a long time, Russian oilmen needed materials with such specifications and at first they appealed to American suppliers. Designed to meet market requirements, Plastik KS was based on local components that made it up to 10 times cheaper than its Western analogue. Currently, its price is between 160 and 180 rubles per kg. In three years that passed since the chemical had been modified by RITEK-ESPC, sales of this product have increased more than four times reaching 300 t - the amount planned to satisfy the current year market demand.
Acid microemulsions (AME) developed by RITEK-ESPC to treat a formation bottomhole zone are of great demand among specialists from RITEK, LUKOIL and Surgutneftegaz. Following application of AME technology, injectivity is increased on average by 150 percent, the technology application success comes to nearly 70 percent.
Modern Equipment for New Technologies
Development of new chemicals and their updates is largely determined by expansion of the range of applied technologies. That is why RITEK-ESPC positions itself as a service company in such areas as oil recovery enhancement, production stimulation and squeeze cementing. RITEK-ESPC was founded in 2004, after the merge of two RITEK departments. Of the mentioned departments, one specialized in providing services employing POLYSIL and another - in manufacturing RITIN-10 chemical. The new company's main activities included squeeze cementing, elimination of behind-the-casing flow, optimization of producing wells' influx, and increase of injectability.
Wide-scale cooperation with such companies as LUKOIL-Western Siberia, LUKOIL-Permneft, LUKOIL-Коmi, Surgutneftegaz, Таtneft, Rosneft-Purneftegaz, Samaraneftegaz inspires the search of solutions adapted for various geological and technical conditions. RITEK-ESPC's technologies bank contains over ten modern technologies for oil recovery enhancement and well stimulation. Only in 2005, application of advanced technologies to oil companies' well stock resulted in total additional oil recovery of 230500 t.
At present, RITEK-ESPC intends to expand its activities launching equipment manufacturing. Given the company's specialization in squeeze cementing and bottomhole treatment (BHT), it was decided the last year to finance development of innovative technologies.
Among those is a multifunctional pumping unit for cementing jobs. Additionally, it will be used for injection of Plastik KS chemical and water inflow selective limitation. Apart from pumping equipment, the unit is fitted with appliances for fast preparation and injection of composite grouting mixtures suitable for technologies used by the company. Full production control is ensured from the very start of the process. All data are transferred to the regional center or to Moscow for further review.
Another project of the company is the development of two small-size logging units mounted on the SKVAZHINA lab-truck. The units are equipped with fiber-optic cable and designed to perform location search for abnormal intervals in the casing, such as damages or faulty sealing. They will check these intervals using temperature survey, electrical logging, acoustic meters, and perform a visual inspection of production casing with subsurface video-system.
Early in June, RITEK scientific and technical council reviewed an investment project aimed at development of RITEK-ESPC.
"We would like to create a fleet of special pumping equipment to do certain acid treatment," said Viktor Zavolzhskiy, general director of RITEK-ESPC. "Such treatment could replace fracturing that's been in use almost in all oil-producing regions for years," he added. "Basically, all wells suitable for such technologies have already been fractured". Speaking of remaining well stock, acid treatment methods could be applied to 70 percent of wells ensuring considerable effect without mechanical damage." Besides, the cost of fracturing is not comparable to that of acid treatment: while the former today exceeds 2 million rubles, the latter of the same efficiency ranges between 1-1.5 million rubles.
Also, it is worth mentioning that experts on oil recovery and influx stimulation methods favor acid treatment over fracturing as less damaging to wells and consequently proving more beneficial in the long run.