Tribological study of OH- and N-containing imidazoline derivatives as additives in water–glycol

Tribological properties of two hydroxyl- and only active nitrogen-containing water-soluble imidazoline derivatives, benzotriazole-containing imidazoline (BML) and caprylic acid-containing imidazoline (CML), as lubrication additive in water–glycol hydraulic fluid were evaluated with a four-ball tester. And the antirust and anticorrosion behaviors were also investigated. Results show that BML and CML were able to remarkably improve the antirust properties of water–glycol fluid when added at a low adding concentration, and also these performances of BML was better than CML. All additives exhibited good extreme pressure and antiwear properties, and BML showed better tribological properties than CML. Besides, the difference in the tribological and anticorrosion properties of these derivatives was closely related to their different molecular structures. There exists a synergistic tribological effect between benzotriazole and imidazoline group in the tribological and antiwear performances. Furthermore, significant improvement in the tribological performances of BML was detected and attributed to organic nitrogen compounds, iron oxide, and so on in tribofilm on the worn surfaces.

A Method for the Production of Glycol Recyclates by Physicochemical Processing of Antifreeze Waste Fluids

Antifreeze glycol-based fluids are widely used in various types of industrial systems, equipped with indirect heat exchange systems. A very broad area of the application of glycol fluids is possible due to their primary physicochemical properties, i.e. relatively high boiling point, very low freezing point, and negligible thermal expansion [1,2]. Examples of the application of these fluids may be, e.g. cooling systems and air conditioning, in which glycol fluid is the heat transferring agent [3 – 5].

Four-well comparison in Papua New Guinea: high-risk, high-angle wells demonstrate extended wellbore stability and faster drilling time with inhibitive high-performance water-based fluid

A four-well project located onshore Papua New Guinea provided an opportunity to compare the performance of two inhibitive drilling fluids in the problematic 12¼” interval. Wells A and B were drilled using a conventional KCl/glycol fluid. Wells C and D used a high-performance water-based fluid (HPWBF) containing a shale inhibitor that also provides lubricity. All four wells were drilled with the same rig. The base brine for both fluids was KCl. All hole sections were directionally drilled from vertical to near horizontal by section TD through a claystone interval. Tectonic wellbore breakout was present in all four wells, and the position of the breakout in the wellbore varied from well to well. Well A was regarded as the easiest well to drill due to the breakout being on the sides on the inclined well bore (horizontal), and Well D was regarded as being the most difficult well to drill due to the breakout being located directly on the top and bottom of the wellbore (vertical). Performance comparisons were made using on bottom rates of penetration, tripping times, casing running times, and overall hole section costs. These data have been normalised to remove non hole related NPT events. The KCl/glycol system provided sufficient wellbore stability in Wells A and B with horizontal breakouts and with non-optimal breakouts with very limited openhole exposure. For higher risk wells C and D with non-optimal breakout positions however, the HPWBF offered improved reliability and ensured there was no performance decline. Outstanding performance occurred in Well D where the HPWBF maintained good wellbore stability over a 56-day exposure. Although the KCl/glycol fluid had a lower cost/bbl, improved overall cost savings were achieved by using the HPWBF in the high-risk wells. This paper addresses all operations performed while drilling and casing the 12¼” interval. Possible causes for performance differences are evaluated, taking into account that mud systems represent only one variable. As other variables were introduced progressively, it was possible to back these out to determine mud system effectiveness.