Centrealoil--Acidic surfactant fracturing fluid
With the oilfield production and development, improve the old single well production is the first goal for stabilizing oilfield production. In the reservoir transformation mainly by fracturing and acidification to increase the old fracture seepage area is small, remove scaling and plugging in the seam, moreover in the early development abandon and also attaches great importance to the small thin layer. Due to the reservoir situation after the old well production is complicated and special, the efficiency of single fracturing or acidification is not high. The conventional fracturing modification has difficult in building long slot and high slit cracks on the thin layer. Therefore, it is necessary to develop targeted working liquid to improve the efficiency of old well reconstruction.
The system is developed a new type of acidic fracturing fluid based on the clean fracturing fluid technology. The fracturing fluid can add different types and different concentrations of acid liquid, such as hydrochloric acid, hydrofluoric acid, which is effectively made the acidification and fracturing reached combination. The fracturing fluid is a special modified viscoelastic surfactant, with the characteristics of surfactant of no water insoluble substance, gel breaking liquid with no residue. Therefore, neither form a permanent filter cake in the crack, nor affect the fracture conductivity fluid maintained at 20~100mPa.s (adjustable). The system has good viscoelasticity, strong proppant-carrying capacity, and can reduce the reservoir fracture fracturing after carry acid liquid .The low viscosity and high elastic properties in the numerical simulation of fracture is shown that easy to form long seam and narrow seam high fracture morphology.
When the system encounter the hydrocarbon of formation or is diluted by formation water, it will automatically break, leave no residue, and does not affect sand-pack fracture conductivity. As the system contains a large number of cationic groups, so it can effectively prevent the clay swelling.
Nonionic groups in the system can effectively prevent crude oil and gel breaking liquid emulsification. Due to the main agent of fracturing fluid containing a large number of cationic groups, and also has a certain viscosity, the system corrosion rate meet the industry standards. The application of this technology has been more than 50 wells, and has obvious yield-increasing effect.
Characteristics:
①The system has no residue, no water insoluble substance, low core damage.
②When the system encounter oil and water, the system will automatically break, and does not affect fracture conductivity.
③The system can carry acid liquid and improve the oil phase permeability of non-acid sensitive reservoir
④The system has good viscoelasticity, can meet the requirement of within 65℃for reservoir reconstruction.
⑤For the serious scaling of old wells, it is effective to achieve the combination of fracturing and acidizing.
⑥It is especially suitable for sandstone reservoir old wells transformation, especially small difficult-to-produce reserves and thin interbed transformation.
Centrealoil