With the continuous exploration of oil field reserves in China, the development strength of oil field has been obviously enhanced, and the number of oil wells is also increasing more and more rapidly. Because of the damage to the environment, the treatment technology of the waste produced during drilling has attracted more and more attention. Drilling fluid, as the main waste liquid to be treated in drilling process, has been widely used in pollution-free treatment technology of oil field waste drilling fluid because of the pollution and damage effect of some chemical components contained in it on the environment.
1 Recycling method
The waste drilling fluid can be reused after recovery, storage and treatment by transit station. This method not only avoids the damage of drilling fluid to the environment, but also effectively reduces the cost of drilling fluid in the process of reuse.
1.1 Mechanized recovery units are used to convert drilling fluid into dry-cured dry powder formulations and to reuse the cured dry powder formulations after hydration. Although the hydrated drilling fluids can not reach their original properties, their use as an aggravating agent is still very effective. This method uses more fuel and costs more in the process of curing the drilling fluid into dry powder formulations, which is also a disadvantage of this method.
1.2 Old well drilling fluid reuse technology: this technology is relatively simple, one well after the completion of the drilling fluid can be moved to another similar well to continue to use, then the drilling fluid only need to add some treatment agent to achieve the original performance for re-use. This method does not require mechanical equipment and fuel, the demand for personnel and equipment is low, the cost is low, and the pollution of drilling fluid to the environment is effectively reduced, so this technology has remarkable effect in terms of economic, environmental and engineering benefits. This method is most suitable for the area with high wellhead density. After the completion of the old well, the drilling fluid is transferred by transfer tank truck Using another field utilization, this method urgently needs to solve an urgent problem, that is, how to ensure the multiple reuse of drilling fluid with the minimum investment, which is the most promising and low cost method at present, effectively realizes the reduction of production cost and the improvement of economic benefit of oil wells.
To be continued