浅水湖泊水上煤田钻井液污染分析

为了研究浅水湖泊水上煤田钻探工程中可能发生的钻井液泄漏对水体的污染情况,以淮南顾北矿港河水上勘探为例,实测分析了不同浓度钻井液对污染指标和鲫鱼存活的影响,其中污染指标包括pH值、悬浮物、CODcr、总Cr和Cd。采用保守物质的对流扩散方程,对钻井液输移扩散进行了数值模拟。研究发现,当钻井液浓度小于1 000mg/L时,所测试的污染指标基本上能够达到二级排放标准;当钻井液浓度达到5000mg/L时,鲫鱼死亡率约为原水中养殖的正常死亡率的2倍;钻井液在扩散初期其浓度迅速减少,且水流整体流速越大,则钻井液扩散越快,在扩散后期钻井液会形成高浓度聚集区,钻井液浓度的衰减变慢。

Analysis of Drilling Fluid Pollution from Coal Drilling upon Shallow Lake Surface

In order to study possible drilling fluid leakage pollution to water body during the coal drilling upon shallow lake surface, tak-ing the Huainan Gubei coalmine exploration on water surface as an example, measured and analyzed different concentration drilling flu-ids impact on contamination indexes including pH value, suspended matter, CODcr, total Cr and Cd, as well as carp survival rates. Us-ing conservative matter convective-diffusion equation carried out numerical simulation of drilling fluid transport and diffusion. The study has shown that when drilling fluid concentration less than 1000mg/L, tested contamination indices basically can reach effluent standard category II;when the concentration up to 5000mg/L, carp mortality can be twice the carp living in original water. During ini-tial diffusion stage, drilling fluid concentration decreasing quickly, the large the overall water velocity, the quick the drilling fluid diffu-sion, during the later stage, will form high concentration gathering area of drilling fluid, drilling fluid concentration attenuation slowing down.