Surface Water Environmental Impact Analysis On Solidification Treatment Of Drilling Mud

After completion of drilling operation, a large amount of waste drilling mud is produced, and this will severely pollute the surrounding ground waters once directly discharged:The salt, alkali and rock salt attached will result in soil hardening around the water, which can cause the plants and crops grow abnormally, and even the soil can not be re-cultivated; Heavy metal, chemical additives and the products after degradation of organic substances will cause water eutrophication once they enter the water, and influence growth of algae and aquatic animals and damage the aquatic ecosystem. At the same time, those pollutants will be enriched due to absorption of aquatic animals and plants, which is hazardous for life and health of human, the upper level of food chain. Chemical solidification filling method is currently an effective method for treating waste mud. It perfectly contains and fixes the pollutants in the waste mud through the effect of solidification agent, and avoids the pollutants moving outward and causing adverse influence upon the surrounding water environment.In this paper, five representative drilling platforms in Sichuan are selected. Through comparison on the treatment efficiency of different cement solidification agents, including comparison on properties of solidification samples and monitoring data of pollution factors of solidification leach liquid, it analyzes the efficiency of the waste drilling solidification treatment process by using the water-base mud as the original mud and analyzes the impact on the surrounding water environment from existing common solidification units.It is indicated from the survey of pollution factors leached from solidified body of5well sites that all the monitoring data including chemical oxygen demands, petroleum, chloride, chroma and hexavalent chromium can reach emission standard of Class I of Integrated Wastewater Discharge Standard (GB8978-1996) except that PH values of3well sites are slightly higher than the standard. This Paper adopts multi-factor assessment method, i.e. improved Nemerow index method through which comprehensive pollution level of several pollutants and weight proportion of different pollution factors are taken into consideration and water environment quality can be directly and completely reflected. It through application of improved Nemerow index method comes to the conclusion that the comprehensive pollution degree of leached liquid of solidified body of well site1is greater than that of other well sites.Well site1is taken for an example. Mud solidification treatment and analysis of impact on surrounding environment shall be conducted. It through comparison of previous and latter monitoring data of surface water body of well site1gets to know that there is no obvious change regarding surrounding water quality. The changed part of monitoring data is also attributable to precipitation and human factors. In addition, it is through field inspection observed that crops which are planted on debris basin after reclaimation are growing well. It through the above comes to the conclusion that solidification treatment of existing drilling mud of Sichuan region does not have great impact on surrounding surface water environment.