Squeeze treatment

The squeeze treatment is a method of continuously feeding an inhibitor into oil or gas wells. A quantity of inhibitor is pumped into a well and is followed by sufficient solvent to force the inhibitor into the formation, or inhibitor is mixed in oU, aromatic solvent, or water at the proper ratio, pumped into the tubing and displaced to the bottom, followed by sufficient fluid to overdisplace the mixture into the formation by 3500 to 11 500 liters. The inhibitor is absorbed by the formation, from which it slowly escapes to inhibit the produced fluids. Protection apphed in this manner has been known to last for a year. 

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E. J. Mackay and K. S. Sorbie. Modelling scale inhibitor squeeze treatments in high crossflow horizontal wells. J Can Petrol Technol, 39(10) 47-51, October 1998. 

Formation Damage at Prudhoe Bay, Alaska, by Inhibitor Squeeze Treatment," J. Pet. Technol.. June 1985, 1019-1034. 

Price, R. and Gaber, B. Controlled Release of Active Agents Using Inorganic Tubules, US Patent 5,651,976. Price, R. Sustained Delivery of Active Compounds from Tubules with Rational Control, US Patent 5,705,191. Price, R. Method of Controlled Release and Controlled Release Microstructures, US Patent 6,280,759. Price, R. Efficient Method for Subsurface Treatment, Including Squeeze Treatment, US Patent6, 401,816. 

Near-well treatments, in which chemicals are injected into producing and sometimes injector wells, where they are intended to react with the reservoir rock. Well stimulation techniques such as acidization, for example, are intended to increase the formation s permeability. Alternatively, producing wells may receive squeeze treatments in which a mineral scale inhibitor is injected into the formation. In this case, the treatment is designed so that the inhibitor sorbs onto mineral surfaces, where it can gradually desorb into the formation water during production. 

Sulfate scaling poses a special problem in oil fields of the North Sea (e.g., Todd and Yuan, 1990, 1992 Yuan et al., 1994), where formation fluids are notably rich in barium and strontium. The scale can reduce permeability in the formation, clog the wellbore and production tubing, and cause safety equipment (such as pressure release valves) to malfunction. To try to prevent scale from forming, reservoir engineers use chemical inhibitors such as phosphonate (a family of organic phosphorus compounds) in squeeze treatments, as described in the introduction to this chapter. 

Sorbie, K. S., M. Yuan and M. M. Jordan, 1994, Application of a scale inhibitor squeeze model to improve field squeeze treatment design (SPE paper 28885). European Petroleum Conference Proceedings Volume (vol. 2 of 2), Society of Petroleum Engineers, Richardson, TX, pp. 179-191. 

Volatilization has already been discussed under VPIs in connection with boilers and closed containers. Another application is the inhibition of gas condensate corrosion. However, the treatment here is essentially the same as used in batch or squeeze treatments (Yin 2010). 

Acrolein is an extremely reactive molecule that is used to perform several different functions in the oilfield. It is an effective biocide at low use concentrations and will also reduce hydrogen sulfide concentrations. It is also used in squeeze treatments to aid in the dissolution of iron sulfide. 

Nasr-El-Din, H. A., Rosser, H. R. and Al-Jawfi, M. S., 2000. Formation Damage Resulting from Biocide/Corrosion Inhibitor Squeeze Treatments, SPE paper 58803 presented at the 2000 SPE International Symposium on Formation Damage held in Layette, LA 23 - 24 February, 2000. 

Summarize the squeeze treatment process in five important steps. 

Squeeze treatment A method of continuous feeding an inhibitor in an oil well by pumping a quantity of inhibitor into the well. The inhibitor is absorbed by the formation from which it slowly escapes to inhibit the produced fluids. 

Squeeze treatments with a calcium carbonate scale inhibitor may be accomplished separately from acidizing. They may be recommended following acid treatment or acid cleanup of the formation. 

Wells with low bottom-hole pressure cannot withstand the hydrostatic head. They can be treated the same as above, however, except the inhibitor-diluent mix is atomized with nitrogen and then displaced and over-displaced with nitrogen. Squeeze treatment with nitrogen is costly because of the equipment required. It may be possible to use high-pressure natural gas for the squeeze instead of expensive nitrogen. 

It should be borne in mind that the squeeze treatment can damage the oU well. Loosely consolidated sand win move and is worse when the flow is reserved. Squeezing this type of well brings the loose sand into the flow channels and into the well. The use of fresh water should be avoided with formations containing clay this will cause the clay to swell. 

Uses Dispersant, fluid loss control aid, scale inhibitor, aids cuttings suspension, removal from the hole for oil field applies. scale inhibitor for production squeeze treatments... 

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