Synergistic Effect of Polyaspartate and Polyethylene Glycol on Lubrication Performance of the Water-Based Drilling Mud

Abstract

The poor lubrication performance of water-based drilling mud hinders its application in the drilling process of extended, reach horizontal wells. To overcome this shortcoming, polyaspartate (PA) and poly­(ethylene glycol) (PEG) were used to improve the lubrication performance of the water-based drilling mud. The conventional performances, lubrication performance, and micro-image of antiwear steel balls of the modified water-based drilling mud were analyzed. The results show that the coefficient of friction (COF) of the water-based drilling mud mixed with 10% PA and 5% PEG was the lowest, reaching 0.094, the reduction rate of COF was 63.1%, and the drilling mud cake stuck factor was also the lowest. The addition of PA and PEG had no effect on the rheological properties of water-based drilling mud and also can significantly reduce the filtrate volume; the reduction rate of the filtrate volume reached 43.5%. All of these result from the synergistic effect of PA and PEG; they are adsorbed on the metal surface and the mud cake to form a lubricating film. At the same time, the lubricants also changed the appearance of the solid particles in the mud cake, which reduced the friction between the mud cake and the drilling tool. Moreover, effects of the influence of drilling mud properties on lubricants (alkali metal ions, pH, temperature, and drilling mud density) were examined. The water-based drilling fluid with the synergistic effect of PEG and PA shows similar lubrication performance as the oil-based drilling fluid and can meet the technical requirements of corresponding horizontal wells.

Development of a High-Performance Drilling Fluid Additive for Application in Indian Shale Gas Formations

“…PEG used in this experiment has an average molecular weight of 20,000 g/mol. The hydroxyl groups at the end of the long-chain PEG molecule adsorb on the surface of the mud cake, which effectively blocks the micropores and reduces the filtrate volume …”

Advanced developments in environmentally friendly lubricants for water-based drilling fluid: a review

“…3b ), thus forming a “ball bearing effect” on the surface of the mud cake, effectively reducing the frictional resistance between the drilling tool and the mud cake. 54 …”

“…3b), thus forming a "ball bearing effect" on the surface of the mud cake, effectively reducing the frictional resistance between the drilling tool and the mud cake. 54 The effects of the above lubricants on the rheological properties of water-based drilling uids are shown in Table 4. The use of polyalcohols alone generally does not cause a large change in the rheological properties of the drilling uid, but its use in combination with other lubricants may cause changes in the rheological properties.…”

“…Shutesh et al reacted nanoparticles with boron and suspended them in an ester-based organic carrier to prepare a boron-based nanomaterial enhanced additive PQCB. PQCB It has been used in oil wells in the Gulf of Mexico, and the complex polyol uid produced by the reaction of methyl glucoside and polyglycerol can improve the stability of the wellbore Fatty alcohol 53 Fatty alcohols can inhibit foam generation and reduce the impact on other properties of drilling uids Polyethylene glycol (PEG) 10 PEG lubricant has no obvious effect on AV, PV, and YP of drilling uid, and has been successfully applied in Sulige gas eld Polyaspartic acid (PA) and polyethylene glycol (PEG) 54 The use of PA and PEG alone has little effect on the rheological properties of water-based drilling uids. However, the combined use of PA and PEG has a synergistic effect on the rheology of the drilling uid.…”

Lubricity and Rheological Properties of Highly Dispersed Graphite in Clay-Water-Based Drilling Fluids

“…The main lubricants used in drilling fluid in this field are mineral oil and vegetable oil, which cause environmental pollution, and have been gradually replaced. Lubricating additives have high surface activity, and improve surface adhesion and lubricity [ 15 , 16 ]. Therefore, a water-based drilling fluid mud with lubricating additives as designed.…”