Assessing the feasibility of enzyme technology for the biodegradation of polymers used in hydraulic fracturing operations

碳氢化合物，如天然气中发现的甲烷、乙烷和丙烷，是从地下深处的储藏层中回收的。在某些情况下，通过在储集层中钻一系列井可以相对容易地获取碳氢化合物。碳氢化合物很容易从储集层移动到井中，在那里收集它们。这些油田被称为常规油气藏。然而，在某些情况下，天然气不容易进入油井，因此仅仅钻探油井是不够的。这些非常规储集层需要更多的工作来回收碳氢化合物。一种被用来释放碳氢化合物的方法被称为水力压裂。在这种方法中，液体在高压下被泵入油井并进入储集岩中，使其破裂。以这种方式压裂储层有利于碳氢化合物的移动。一次 液体被带走，释放出的碳氢化合物可以进入油井并被收集。压裂中使用的液体通常含有有助于压裂过程的聚合物，如聚丙烯酰胺。然而，随之而来的一个问题是，残留的聚合物经常留在裂缝中，随着时间的推移积累，阻止碳氢化合物流入油井。已经对热和化学方法进行了评估，以分解这种聚合物，但这些方法效率低、成本高，而且可能会产生有毒的副产品。在这个项目中，我们建议使用生物方法来降解聚合物。我们的初步结果表明，自然界中有微生物含有能够自然分解这些聚合物的酶。我们的目标是鉴定和培养这些微生物，然后评估它们的酶是否能将特定的聚合物分解成无害的 储油层条件下的产品。我们将在一种我们将设计和建造的新型设备中创造这些条件。如果成功，这个项目将给加拿大带来极大的好处。非常规油气藏的碳氢化合物产量增加将产生积极的经济影响。该项目还将在新的多学科领域对个人进行培训。最后，它将表明，学术界和工业界可以合作，为石油和天然气行业的问题开发环境友好的、基于生物的解决方案。

Hydrocarbons, such as the methane, ethane and propane found in natural gas, are recovered from reservoirs deep under the ground. In some cases, the hydrocarbon can be accessed relatively easily by drilling a series of wells into a reservoir. The hydrocarbons readily move from the reservoir into the wells where they are collected. These are known as conventional reservoirs. However, in some cases the gas does not easily move into a well, and thus simply drilling the well is not sufficient. These unconventional reservoirs require more work to recover the hydrocarbons. One approach that has been taken to free the hydrocarbons is called hydraulic fracturing. In this approach, liquids are pumped at high pressure down a well and into the reservoir rock causing it to crack. Fracturing the reservoir in this manner facilitates the movement of hydrocarbons. Once the liquid is removed, the freed hydrocarbon can enter the well and be collected. The liquid used in fracturing typically contains polymers, such as polyacrylamide, which help in the process. However, one problem that arises is that residual polymer often remains in the fractures, accumulating over time, preventing the hydrocarbon from flowing into the well. Thermal and chemical approaches have been evaluated to break down this polymer, but they are inefficient, expensive, and can result in toxic by-products. In this project, we propose to use a biological approach to degrade the polymers. Our preliminary results suggest that there are microbes in nature that contain enzymes which can naturally break down these polymers. Our aim here is to identify and grow these microbes, and then evaluate if their enzymes can break down specific polymers to harmless products under reservoir conditions. We will create these conditions in a novel device that we will design and construct. If successful, this project will have great benefit to Canada. Increased hydrocarbon production from unconventional reservoirs will have a positive economic impact. This project will also result in the training of individuals in new multidisciplinary areas. Finally, it will show that academia and industry can collaborate to develop environmentally friendly, biology-based solutions to problems in the oil and gas industry.