Special lubricating grease for high-dropping-point extreme-pressure drill collar threads

Abstract

The invention provides special lubricating grease for high-dropping-point extreme-pressure drill collar threads. The special lubricating grease for the high-dropping-point extreme-pressure drill collar threads comprises the following components in percentage by weight: 22-27% of synthetic calcium sulfonate, 4-6% acetic acid, 3-5%of dodecanoic acid, 1.5-3% of micro-powder boric acid, 0.8-1.2% of calcium hydroxide, 23-28% of refined paraffin base oil, 22-25% of poly-alpha olefin oil, 0.1-0.4% of micro-powder graphene, 3-6% of antimony dialkyl dithiocarbamate, 2-5% of molybdenum oxysulfide di-n-butyldithiocarbamate, 1-4% of zinc dialkyl dithiophosphate and 1-4% of copper thiophosphate. The special lubricating grease for the high-dropping-point extreme-pressure drill collar threads has the advantages of extreme-pressure wear resistance, oxidation resistance, medium resistance, lubricating property and excellent protective performance, and can ensure the normal drilling requirement of a drill collar.

Description

technical field [0001] The invention relates to the technical field of lubricating materials, in particular to a special lubricating grease for high drop point extreme pressure drill collar threads. Background technique [0002] During the drilling of oil, natural gas and shale gas wells, the threaded joints of drill collars must be coated with a lubricating and protective material grease that can adapt to the depth of the well. With the exploration and exploitation of oil, natural gas and cleaner energy shale gas, The performance requirements of drill collar thread grease are mentioned to a higher level, so as to ensure that during the drilling process, the requirements for lubrication and protection performance of the drill collar thread parts can be met, and to ensure that the threaded joints have sufficient lubrication during drilling. Lubricity, extreme pressure, anti-wear, anti-oxidation, and anti-interference properties ensure that in the process of continuous high-pr...

AI Technical Summary

Problems solved by technology

[0002] During the drilling of oil, natural gas and shale gas wells, the threaded joints of drill collars must be coated with a lubricating and protective material grease that can adapt to the depth of the well. With the exploration and exploitation of oil, natural gas and cleaner energy shale gas, The performance requirements of drill collar thread grease are mentioned to a higher level, so as to ensure that during the drilling process, the requirements for lubrication and protection performance of the drill collar thread parts can be met, and to ensure that the threaded joints have sufficient lubrication during drilling. Lubricity, extreme pressure, anti-wear, anti-oxidation, and anti-interference properties ensure that in the process of continuous high-pressure drilling, there will be no buckle due to poor protection, and ensure that the drill collar is dismantled after lifting the drill, and when the single piece is thrown, it will not stick Button to prolong the service life. At present, the drill collar thread grease commonly used in the domestic market has the following common features. First, all the drill collar thread grease is SY5198 drill thread grease, and the dropping point of SY5198 drill thread grease is low. At the same time, the standard stipulates that lithium lauryl stearate soap thickener has a dropping point of up to 200°C. Lithium soap grease is generally reversible and can only work below 120°C. It is not suitable for wells below 4000 meters, otherwise Oil and soap are easy to separate, the thread lacks protection, and it is easy to stick to the thread when pulling out the drill. Secondly, the evaporation rate of drill collar thread grease is low. GB / T7325 stipulates ≯2%, while SY5198≤4% is twice the difference, and the evaporation loss Large amount, low oil film retention, easy to stick when removing the drill collar, and the drill collar thread grease is mostly neutral, without inhibiting oxidation, free alkali after neutralizing the acidic body, low extreme pressure and wear resistance