SULFEX ® IN HYDROCARBON BASED DRILLING SOLUTIONS
SULFEX ® additive is a sulfonated bitumen in the form of a sodium salt, which has become soluble in water as a result of a unique sulfonation process. It is a universal reagent for drilling fluid which stabilizes shale formations, significantly improves the lubricating properties of the drilling fluid and reduces filtration in high pressure and temperature conditions, as well as improves wall cake properties in water- and oil-based drilling fluids. The product can be added to most aqueous and hydrocarbon as well as synthetic solutions. SULFEX ® additive has been used in water- and hydrocarbon-based drilling fluids.
MAIN ADVANTAGES OF USING SULFEX ® ADDITIVES IN HYDROCARBON-BASED DRILLING FLUIDS AND SYNTHETIC SOLUTIONS
Improves lubricating properties – reduction of friction force to 30 % at low treatment levels with the addition of SULFEX ®. This applies to metal-to-formation and metal-to-metal contacts.
- Increases temperature stability (safely reduces high pressure and temperature filtration)
- Improves return permeability
- Provides excellent well stability
- Improves quality of the filtration layer and reduces thickness of the wall cake
- Reduces torque and drag (galling/slipping)
- Increases mechanical drilling speed
- Meets the toxicity requirements for production in the coastal areas of the North Sea
- Provides a thin compressible filtration layer
SULFEX ® ADDITIVE FACILITATES REMOVAL OF FILTER CAKE
The filter cake of hydrocarbon-based solutions can be beneficial in drilling permeable rock formations, especially if the well is inclined, exposed to high temperatures, features depleted zones, or there is a risk of formation damage, and the properties of the filtration layer can determine success or failure. Hydrocarbon-based solutions are frequently optimal for use in drilling formations in liquid, despite the claims accompanying the ‘new’ specialized drilling rigs. The use of SULFEX ® additive in hydrocarbon-based drilling fluids not only minimizes the damaging movement of fines but also facilitates removal of filter cake. Many slotted liners and completed wells with installed shakers have demonstrated very successive performance.
The following work demonstrates the ease of filter cake removal using a reference solution containing an acid-type breaker when SULFEX ® additive is introduced into a hydrocarbon- or synthetic-basis drilling fluid. A total of five synthetic solutions have been formulated. All of them were subjected to rotation with heating at 220 °F for 16 hours. All solutions had the same density of 13.65 ppb and an oil-water ratio of 85/15. The filter cake obtained during filtration testing was retained and subsequently used to observe the reaction on immersion in a solution containing an acid-type breaker (consisting of ethylene glycol monobutyl ether [EGMBE], HCl [35 %] and saturated KCl solution). The results of testing demonstrate that the addition of SULFEX ® product to composition No. 1 provides a filtration layer which is readily soluble using a simple breaker solution.
SULFEX® ADDITIVE IN LOW-TOXIC OIL-BASED SOLUTIONS
