水基钻屑特性分析及其土地利用关键问题初探

Characteristic analysis of the waterbased drilling cutting and its preliminary study over the key issues of the corresponding land use

为了合理进行水基钻屑土地利用方案设计,采用X荧光光谱法（XRF）、X衍射光谱法（XRD）、扫描电子显微镜（SEM）等联合测试手段系统分析了水基钻屑的矿物组成、结构体系、理化性质和污染特性,采用改进的层次分析法确定了各指标权重,提出了水基钻屑土地利用面临的关键问题。结果表明：水基钻屑含有大量成土元素和矿物,具有良好的矿物质和养分基础,但其质地砂性强,无微孔结构,结构性差;重金属、苯并（a）芘（Ba P）、可吸附有机卤化物（AOX）等污染物指标满足相关标准,但矿物油质量比超出HJ 350—2007《展览会用地土壤环境质量评价标准限值》0.28倍,高出森林土壤背景值15.43倍;全盐量超出CJ/T 340—2016《绿化种植标准》10.36倍,高出森林土壤背景值16.04倍;矿物组成、结构体系、理化性质及污染特性在土地利用中的权重系数分别为0.055、0.118、0.263、0.564。研究表明,水基钻屑土地利用亟待解决的关键问题是控制污染物累积与扩散、降低盐分、协调增加养分含量、改善结构体系及合理进行工程设计。

In order to reasonably design the land application plan of water-based drilling cuttings,the present paper has done a systematic analysis of some characteristic features of WBDC by means of the associated testing methods,such as by way of using the X-ray fluorescence spectrometry（ XRF）,the X-ray diffraction（ XRD）,and the electronic scanning microscope（ ESM）. The above said corresponding characteristic features may include the mineral composition,the structural system,the physicochemical properties and the pollution traits. And,then,we have managed to work out the weight coefficient of the said indexes above mentioned in the process of land application project with an improved analytic hierarchical process method（ IAHP）. The results of our calculation indicate that the WBDC method has been found with lots of soil-constituting elements and minerals so as to form a wellmixed mineral and nutrient matter foundation of WBDC,whereas the structural system of WBDC seems to be relatively poor because its texture belongs to the sandy sort with no micro-porous structure. Furthermore,the content rate of heavy metal elements,benzo（ a） pyrene（ Ba P） and adsorbable organic halides（ AOX） of WBDC proves to be basically meet the relevant Environmental quality standard of the given soil. Nevertheless,the petroleum content rate of WBDC turn out to be over the maximum allowable content rate in terms of the HJ 350—2007 standard of the soil quality at 0. 28 times for the exhibition sites and 15. 43 times over the forest soil background content rate. Besides,the total salt content of WBDC proves to be 10. 36 times beyond the maximal limit stipulated by the CJ/T 340—2016 Planting Soil for the Green Plants and 16. 04 times for the forest soil background content. What is more,the weight coefficients of the mineral composition,the structural system,the physicochemical properties and the pollution features can be literally listed as 0. 055,0. 118,0. 263 and 0. 564,respectively,well in accord with the calculation results of IAHP method. In the end,on the basis of the comprehensive characteristic analysis and the weight coefficient calculation,it would be better to put forward some key problems to be solved to improve the WBDC land application availability,which may help to control the pollutant accumulation and diffusion status-in-situ by reducing the total salt content rate and increasing the nutrient matter content rate such as by reducing the effective nitrogen and available phosphorus in phase so as to improve the structural system by taking reasonable engineering measures.