Environment-friendly temperature-resistant salt-resistant plugging filtrate loss reducer applied to low-solid-phase saltwater drilling fluid and preparation method of plugging filtrate loss reducer

Abstract

The invention relates to an environment-friendly temperature-resistant salt-resistant plugging filtrate loss reducer applied to low-solid-phase saltwater drilling fluid and a preparation method of theplugging filtrate loss reducer. The plugging filtrate loss reducer is prepared from the following raw materials: natural macromolecular polysaccharide, wood powder, an antioxidant, a cross-linking agent and a conditioning agent. The plugging filtrate loss reducer prepared by the method has double effects of carrying out film formation filtrate loss reduction and plugging filtrate loss reduction,has certain self-emulsification performance, lubrication performance, inhibition performance and non-tackifying performance, is high in capability of improving mud cake quality and high in capabilityof plugging, further has excellent temperature resistance, excellent salt resistance and high capability of reducing filtrate loss, is prepared by a one-pot process, is produced by a convenient process, is high in cost performance, is environmentally friendly in the production and usage processes, and is especially applicable to various types of low-solid-phase saltwater drilling fluid systems.

Description

Technical field [0001] The invention relates to the field of treatment agents for water-based drilling fluids in oil fields, in particular to an environment-friendly temperature-resistant and salt-resistant plugging fluid loss reduction agent for low-solid brine drilling fluids used in petroleum drilling and a preparation method thereof. Background technique [0002] With the development of the petroleum industry and the continuous growth of petroleum demand, oil and gas exploration and development are gradually developing into deep strata and offshore. The difficulty of drilling engineering is becoming more and more difficult. The increasing environmental pressure puts environmental protection on water-based drilling fluids and drilling fluid treatment agents. Biodegradability puts forward higher requirements. Water-based drilling fluid is a complex polymer suspension system composed of water, bentonite, inorganic and organic treatment agents, cuttings and some mineral materials...

AI Technical Summary

Problems solved by technology

However, the existing natural polymer fluid loss additives and anti-slumping agents still generally have the defects of insufficient temperature and salt resistance in actual use, and the existing fluid loss additives for water-based drilling fluids often have viscosity increase, The production process is cumbersome, the cost is high, the use of a large amount of organic solvents and the environmental problems of poor biodegradability, etc.

For example: Chinese Patent Publication No. CN103013461A proposes a kind of white pitch for drilling fluid and preparation method thereof, is that first paraffin, alkylphenol polyoxyethylene ether, Polyethylene Glycol, stearic acid are added in the reactor to react, and then Adding polyacrylamide, stirring at constant temperature; finally adding light calcium carbonate evenly, stirring at constant temperature for a certain period of time, discharging, spraying and granulating to obtain white asphalt, but the softening point of the product obtained by this technology is low, generally less than 60°C, which It is not suitable for drilling exploration wells and development wells with high bottom hole temperature, that is, the ability to resist high temperature is insufficient, and its ability to resist salt and calcium is insufficient

Chinese Patent Publication No. CN104194743A proposes an anti-slump agent for oilfield drilling fluid and its preparation method and application. It is prepared by stirring and reacting high-carbon fatty acids, high-carbon fatty alcohols and polyhydric alcohols at 70-105°C in a certain proportion. The method of using non-fluorescent white asphalt anti-slump agent for drilling fluid has good plugging and anti-slump performance, can effectively improve the quality of drilling fluid mud cake, has no biological toxicity, and has a wide range of softening points, which can be applied to different well bottom temperatures. Exploration wells and development wells, but their ability to resist high temperature and salt is insufficient, and the ability to plug and reduce fluid loss for solid-free drilling fluid is particularly poor, and the raw materials are expensive, and the product is not cost-effective

Chinese Patent Publication No. CN101602938A proposes a cellulose-based drilling fluid fluid loss control agent and its preparation method, which is a method for preparing a cellulose-based fluid loss control agent with a certain salt resistance ability by using existing known techniques and equipment, but does not mention and high temperature resistance, and still cannot solve the problems of large amount of organic solvent usage, product post-treatment desalination, etc.

Chinese patent authorization numbers ZL 201510868207.5 and ZL201510868061.4 respectively proposed a slurry process method and a kneading process method for preparing water-based drilling fluid fluid loss additives using anaerobic fermentation biogas residues, which are by-product biogas residues, natural Plant fiber is used as the raw material, and the method of preparing an environment-friendly fluid loss control agent has a certain resistance to temperature and salt after an alkalization reaction occurs through an alkalinizing agent and a crosslinking agent, and then an etherification reaction occurs by adding an etherifying agent. effect, low price, and environment-friendly during production and use, but it still fails to solve the problems of using organic solvents in the reaction process

Chinese patent publication number CN103740342A has proposed a kind of anti-high temperature anti-salt fluid loss reducer and preparation method thereof, is to utilize plant fiber, acrylic, sulfomethyl phenolic resin co-hydrolysis to prepare the method for drilling fluid anti-high temperature fluid loss reducer, although has Good temperature and salt resistance effect, but it adds a large amount of synthetic polymers, especially the phenolic resin component that is difficult to degrade, which is not conducive to the biodegradation of the product of the invention, and the environmental friendliness is not enough, which will bring problems during use. Certain problems, and the cost is high

Chinese Patent Publication No. CN103045188A proposes a plugging type fluid loss reducer for water-based drilling fluid and its preparation method, which is to use polymer modified oxidized asphalt, modifier and auxiliary fluid loss reducer as raw materials, through simple A plugging-type fluid loss control agent can be prepared by surface modification and dry mixing process, which has excellent plugging fluid loss control performance, the reduction rate is as high as 80%, forms a dense and tough mud cake, and the high temperature of asphalt The characteristics of softening and deformation can seal formation fractures and fissures in time, and the appropriate product formula can be selected according to the characteristics of the application formation and the temperature of the well section. It is flexible in use, simple in production technology, mild in conditions, high in production efficiency, and low in cost; but its reaction is essentially a powder The surface modification of the material is not as uniform and sufficient as the solution method, and the production is affected by many factors, and dust is generated during the production process to pollute the environment; more importantly, the use of black-colored polymer-modified asphalt raw materials makes the invention The product is also black, and the on-site use will be subject to environmental protection restrictions

However, for low-density drilling fluid systems such as low-solids freshwater drilling fluids, low-solids brine drilling fluids, and solids-free brine drilling fluids, because the content of bentonite is low or even does not contain bentonite, the mud cake formed is generally not enough. Dense, poor quality, poor plugging performance of filter cake, large fluid loss, so this kind of drilling fluid system especially needs to add temperature and salt resistance plugging fluid loss reducer

However, in the actual use of the existing natural polymer fluid loss additives and anti-slump agents, the above-mentioned defects or deficiencies generally exist, such as the defect of insufficient temperature and salt resistance, and the existing water-based drilling fluid fluid loss additives There are also problems such as thickening, cumbersome production process, high cost and not environmental protection.

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