Tait R D, Maxon C L, Parr T D, Newton F C
Exxon Mobil Corporation, 22777 Springwoods Village Parkway, Spring, TX 77389, USA.
Maxon Consulting, 2546 San Clemente Terrace, San Diego, CA 92122, USA.
Mar Pollut Bull. 2016 Sep 15;110(1):520-527. doi: 10.1016/j.marpolbul.2016.02.079. Epub 2016 Jul 11.
The effects of linear alpha olefin (LAO) nonaqueous drilling fluid on benthic macrofauna were assessed over a six year period at a southern Caspian Sea petroleum exploration site. A wide-ranging, pre-drilling survey identified a relatively diverse shelf-depth macrofauna numerically dominated by amphipods, cumaceans, and gastropods that transitioned to a less diverse assemblage dominated by hypoxia-tolerant annelid worms and motile ostracods with increasing depth. After drilling, a similar transition in macrofauna assemblage was observed with increasing concentration of LAO proximate to the shelf-depth well site. Post-drilling results were consistent with a hypothesis of hypoxia from microbial degradation of LAO, supported by the presence of bacterial mats and lack of oxygen penetration in surface sediment. Chemical and biological recoveries at ≥200m distance from the well site were evident 33months after drilling ceased. Our findings show the importance of monitoring recovery over time and understanding macrofauna community structure prior to drilling.
在里海南部的一个石油勘探地点，对线性α-烯烃（LAO）非水基钻井液对底栖大型动物的影响进行了为期六年的评估。一项广泛的钻探前调查发现，在陆架深度区域存在相对多样的大型动物，在数量上以端足类动物、涟虫类动物和腹足纲动物为主，随着深度增加，转变为一个多样性较低的群落，以耐缺氧环节蠕虫和活动的介形虫为主。钻探后，在靠近陆架深度井口的区域，随着LAO浓度的增加，大型动物群落也出现了类似的转变。钻探后的结果与LAO微生物降解导致缺氧的假设一致，证据是存在细菌垫以及表层沉积物中缺乏氧气渗透。在钻井停止33个月后，在距离井口≥200米处，化学和生物恢复情况明显。我们的研究结果表明了随着时间监测恢复情况以及在钻探前了解大型动物群落结构的重要性。
