The Research And Application Of Environmentally Friendly Completion Fluid

For the environmentally friendly completion fluid, it is necessary to possess a higher density and thermostability, as well as a low rate of corrosion. From the perspective of environmental protection, the completion fluid has the following advantages: low biological toxicity, harmlessness to humanbeings, tiny influence on water bioms, easily biological degradability, and small bioaccumulation, as with the recyclability and the reusability. On the other hand considering the following development of oil fields with much more and bigger difficulties, completion fluid technically need to be innovated, thus we can make perfect technical reserves for the following oilfield development. And therefore, the development of non-toxic, highly-thermostable and environmentally-friendly completion fluids has become a matter of urgency.This paper analyzes the relevant knowledge, research methods and the status quo of the present completion fluid both domestic and international. Also the deficiencies'and shortcomings'existences of the current completion fluid are discovered, according to which, a new economical and environmentally friendly completion fluid with a wide range of application and dissemination is being researched through a variety of research methods, a large number of indoor experiments, and through field applications.In this paper, three types of current conventional high-density brine completion fluid are researched, which respectively are bromine completion fluid, non-bromine completion fluid and organic brine completion fluid. Also the paper shows the research of influencing factors on oil filled bushing and underground equipment, and the analysis of the resistance in the completion process and those obstructions, and so on. According to the research of these three types of completion fluid systems, we produce an environmentally friendly completion fluid, which is based on a composite salt heavy weight additive of the low-carbon hydrocarbon organic polymer (A salt for short), plus with clay stabilizer, corrosion inhibitor, fluid loss additive and some other ingredients. Then a systematic evaluation is carried on to show whether the properties of this new completion fluid are in line with the requirements of the construction and environmental protection, such as the density, the thermostability, the rate of corrosion, etc. The result shows that the production of the new completion fluid is great, as well as the exciting application results from seven gas wells of Daqing Oilfield.