未开发油气田地表烃氧化菌空间定量分布

利用Real-time PCR技术,分别对非油气田对照区域、未开发油田、未开发气田地表30、60、100、150、200 cm深度的甲烷氧化菌、C5～C16烃氧化菌进行定量研究,目的在于加深对该类型区域烃氧化菌空间分布特征的了解,为微生物油气勘探技术的发展提供基础资料.结果表明,气田区域甲烷氧化菌(pmoA)含量为1.34E+04～3.90E+05 copies.g-1,并随深度的加深逐渐减少;油田仅为3.14E+02～4.32E+03 copies.g-1.100～200 cm深度,油田C5～C16烃氧化菌(alkB)含量为1.38E+07～3.61E+07 copies.g-1,高于等深度对照(4.24E+06～2.14E+07 copies.g-1)和气田区域(5.82E+06～3.52E+07copies.g-1).甲烷氧化菌分布受全氮、有机碳、pH影响显著,相关系数分别为0.859、0.631、-0.549,而C5～C16烃氧化菌分布受环境因素影响相对较小.100～200 cm深度范围内,该区域全氮、有机碳、pH等理化因素相对稳定,烃氧化菌含量在不同深度间差异较小.因此,本研究表明,气田区域具有明显的甲烷氧化菌异常,油田在100 cm以下深度具有一定的C5～C16烃氧化菌异常;100～200 cm更适于作为统一取样深度进行大范围定量调查,但仍需要进一步的验证.

Spatial Quantitative Distribution of Hydrocarbon-Oxidizing Bacteria of Unexploited Oil and Gas Fields

Spatial quantitative distribution of methanotrophs and C₅-C₁₆ hydrocarbon-oxidizing bacteria of different depths (30, 60, 100, 150, 200 cm) from the unexploited oilfield, gas field and control area was studied using Real-time PCR. The objectives of this study were to understand the quantitative distribution of hydrocarbon-oxidizing bacteria in the regions of unexploited oil and gas fields, and provide basic information for the development of oil and gas exploration techniques. The results showed that the gas field area had higher content of methanotrophs (pmoA), 1.34E+04-3.90E+05 copies·g^-1, and the copies of pmoA decreased with depths. Compared with that in the gas field, it was lower with only 3.14E+02-4.32E+03 copies·g^-1 in the oilfield. Remarkably, the oilfield had a relatively higher content of C₅-C₁₆ hydrocarbon-oxidizing bacteria (alkB) with 1.38E+07-3.61E+07 copies·g^-1 soil below the depth of 100 cm than that in the gas field(5.82E+06-3.52E+07 copies·g^-1) and the control area(4.24E+06-2.14E+07 copies·g^-1). The distribution of methanotrophs was significantly affected by the total nitrogen, organic carbon, pH with correlation coefficients were 0.859,0.631 and -0.549 respectively. Within the depth of 100-200 cm, where physichemical properties such as total nitrogen, organic carbon, pH were relatively stable, the content of methanotrophs and C₅-C₁₆ hydrocarbon-oxidizing bacteria at different depths varied little. Furthermore, there was indeed abnormal methanotrophs in the gas field and abnormal C₅-C₁₆ hydrocarbon-oxidizing bacteria in the oilfield below the depth of 100 cm. Besides 100-200 cm was more suitable as the oil-gas exploration sampling depth in this study which also required further validation.