Enhanced oil recovery from productive formations is a primary innovative goal faced by oil producers. It can be reached only by implementing new modern techniques and technologies.
Due to temporary well plugging by linked polymers and viscoelastic systems (SP) of the most permeable productive layers of the section, there occur a drop in water consumption by washed high-permeability layers with anomalously high rate of reserve recovery, reduction of liquid rate and increase of pressure draw down in producing wells.
As a result of pressure differential increase between injection and recovery zones, reverse in place filtration flows direction, the active reserve recovery process involves oil saturated sublayers of low permeability and water content, not or partially covered by water flood before.
It results in wider producing layers coverage and oil production increase.
It helps to inject polymer composition and then disperse phase into the intake well with bottom water overflush. As a result of such injection each fluid component chooses a separate layer due to its selective property according to the agent particle size and seals it.
The use of GOS-1technology helps to process new sublayers and recover challenged reserves.
Special viscoelastic mud, which is added to the solution and overflush fluids forms gel in highly-porous and water flooded intervals with wide range of strength and blocking properties.
It improves oil treatment from difficult layers and increase oil production from the formation.
This method involves subsequent water nitric solution injection with addition of polymers and hydrochloric acid or CaCl2, which are added to the formation by water plug. The gel is formed from sodium silicate in the acid environment. The gel is formed only in water flooded intervals, which leads to redistribution of the injected water and connection to the development of previously drained, oil-saturated intervals and stagnant zones of the formation. Addition of hydrolized polyacrylamides contributes to greater gel stability in the reservoir conditions.
Physic-chemical nature of gel-forming systems based on the formation of gel aluminum hydroxide in the oil layer, which isolates free from oil, high-permeability areas, and thereby contributes to the operation of low-permeable areas of the reservoir and interlayers. And received ammonium salts react with the oil components and destroy the asphalting structure, thereby increasing oil production.
The technology of enhancing oil recovery with application of the emulsion compositions is injected through injection wells or MGPS into the reservoir rim of the emulsifier.
Partially clogging the most permeable layers, emulsion systems redistribute the flow of injection water in streaks with low permeability, engaging or promoting their participation in development. In addition, some components of the emulsion composition, provide hydrophobic effect on the rock surface by reducing the permeability of water in the reservoir flooded areas, which also contributes to the redistribution of the injected water flow and, accordingly, prevents water flows into the producing wells.
Impact technology of dispersed fibrous — polymer composition is suitable for any formation temperature. The preferred reservoir temperature is from 15 to 85 degree Celsius and the highest permeability layer, and correspondingly high injectivity of more than 600 m3/day.
СКС composition can be used for different goals including efficiency enhancement of commercial wells which are put into operation after drilling.
Also, this technology is well-proven to increase oil extraction from production wells, restoration of the reservoir productivity after all types of repair works and start-up of wells into operation after long periods of inactivity and inaction.
The application effect of this technology is achieved by the destruction of carbonate and other impurities as well as removal of osmotic water and water-oil emulsions. The technology is designed mainly to increase injection capacity and flow rates of the reacting producing wells – that is why the application area of this technology are preferably low permeability marginal layers and their parts.