一种物理吸附烃解吸密封罐及其化探应用效果

油气藏中的轻烃可以以微弱但可检出的量近似垂直地渗漏到地表土壤中，其中一部分烃类以物理吸附态赋存在土壤或岩石颗粒表面。物理吸附烃是反映现今油气藏是否存在的最直接指标之一，因此在油气地球化学勘探中得到了广泛的重视和应用。以往对于提取土壤物理吸附烃的方法主要有密封盐水瓶顶空间轻烃技术和物理吸附气技术，在方法手段上存在一定的缺陷。针对以往技术存在的问题，自行设计、研制一种新型土壤物理吸附烃真空解吸密封罐，集样品全密封、移动活塞负压脱气、正压抽气，能够充分提取土壤、岩石、水介质样品中物理吸附烃组分和含量，装置小巧，操作简单，方便实用，适合批量样品的气体解吸实验。经过对济阳坳陷惠民凹陷南坡临南油田上方野外现场采集的新鲜土壤样品进行处理，获得的烃类组分含量远远高于传统顶空气技术所提取的烃类含量的3～4倍，且C₁-C₅组分齐全，所反映的油气微渗漏异常区与背景区分离明显，先验效果显著，为预测地下油气藏提供了有效的技术指标，具有良好的推广应用前景。

A Seal Jar for Desorbing Physical-Adsorption Hydrocarbons and Its Application Effect

Light hydrocarbons in an underground hydrocarbon reservoir can arrive to the surface in a trace yet detectable amount through near-vertical microseepage,some of which may exist in a physical adsorption state,making physical adsorption light hydrocarbons one of the most direct geochemical indicators in reflecting the present hydrocarbon accumulations.Therefore,physical adsorption hydrocarbon has been widely used in oil and gas geochemical exploration.The headspace gas and the physical adsorption gas techniques have long been used to extract this phase of hydrocarbons,but some technical faults have also been found.A new seal jar for desorbing physical adsorption hydrocarbons has been developed recently,which allows the soil samples treated in a fully sealed state,desorbing the samples by the negative pressure caused by piston movement,and drawing the gas into a positive condition,resulting in a sufficient extraction of the physical adsorption hydrocarbons.The jar,small in volume,easy to operate and portable,is appropriate for analyzing the large amount of samples.Its application in Linnan oilfield in Jiyang depression has shown that the concentration of the hydrocarbons extracted in this way is far higher than that extracted by the traditional method,and the full components of C₁-C₅ show distinct distribution between the microseepage areas and the background areas.The results proved that it can provide an effective geochemical indicator for oil and gas exploration,and has bright application prospect.