Environmental Impact And Solidification Of Water-Based Drilling Fluid

A large number of environmental pollutants are produced in the exploration anddevelopment process of the Petroleum industries, and waste drilling fluid is one of the majorpollutants that has features of high COD, high pH and high salinity. if not handled properly, itwould impact on the environment.The methods of survey and chemistry experiment were used in the research. Firstly, thechemical composition and its Biological toxicity and chemical toxicity of the water-baseddrilling fluid were analyzed according to the information provided by the institute of oildrilling and investigation of the wells being drilled. Then, representative water-based drillingfluid samples of oilfield were collected and its composition and environmental pollutantswere analyzed to evaluate the environmental hazard characteristics. Finally, representativewaste water-based drilling fluid samples of different regions were collected and dealed withthe method of solidification that used in the field. After treatment, the water-based drillingfluids were extracted to evaluate environmental dangers and to determine the applicability ofthe current curing technology.The study found that the majority components of drilling fluids commonly used werenon-toxic, refractory and had impact on the environment, only a few were environmentalacceptability. The detection showed that COD and petroleum of oil field water-based drillingwaste leaching solution exceeded the standard and others were not exceeded, petroleum andother organic matter were the main environmental pollutants. According to the relevantstandards, we can determine the water-based drilling waste was not hazardous characteristicsand can be managed in accordance with the general industrial solid waste. Compared withcirculating water-based drilling fluids, the solid content and density of waste water-baseddrilling fluid decreased slightly and a variety of environmental contaminants content in theleaching solution reduced slightly. Laboratory solidification research and evaluation resultsshowed that contaminants composition in the leaching solution of water-based drilling wastehad changed dramatically and the main indicators had a significant drop after treatment. COD,oil indicators of the leaching solution exceeded when the curing agent dosage was2%and5%,and all indicators of the leaching solution were standard when the curing agent dosage was10%and20%. It achieved the processing requirements when the curing agent dosage was10%and20%. From the analysis of the curing technology adaptability, the curing agent andtechnology being used in the oil field was suitable for curing the typical oil field water-baseddrilling waste.