Towards Realisation of Untapped Oil Resources via Enhanced THAI-CAPRI Process Using Novel Catalysts

在加拿大和委内瑞拉等国存在大量未开发的重油和沥青资源，在英国北海也存在较重的沉积物，随着常规轻质原油产量的下降，这些资源有可能被利用。重油和沥青比传统原油更难回收，需要开采或专门的原地回收技术，然后进行升级，使其适合用作燃料。趾部到跟部空气注入（THAITM）是一种原位燃烧和改质工艺，其中将空气注入水平井以燃烧小部分石油（高达15%）。所产生的热量导致油沿井沿着流动，在井中发生热升级反应，导致油升级（通过4-6 API）。卡普里是THAI的催化添加剂，其中催化剂填充在井周围以实现进一步的催化改质反应，例如加氢处理，然而先前的研究表明催化剂寿命和工艺有效性受到催化剂上的焦炭沉积的限制。此外，在启动之前用粒状催化剂填充井的成本和挑战也使得卡普里方法在经济上不那么有吸引力。当前的提议寻求开发廉价、有效的纳米颗粒催化剂，其可以在操作期间通过空气或作为浆料输送到井中，从而避免了在启动之前用催化剂填充井的要求，颗粒状催化剂上的焦炭沉积。最初，容易获得的氧化铁纳米颗粒将作为基础案例进行测试。纳米颗粒催化剂也将通过将金属负载在细菌上来制备，使用一种方法，其中在细菌培养物的存在下还原含金属的溶液，然后离心并干燥，从而杀死活细菌。该方法具有能够利用废金属溶液的优点，因此有利于从废物源回收金属，并且可以调整该方法以设计具有所需尺寸和性质（例如晶体结构）的纳米颗粒。在这里，我们寻求开发，测试和扩大生物铁催化剂的生产，用于THAI工艺中的石油升级。此外，废路粉尘含有来自车辆催化转换器的排气的催化金属沉积物，这些催化金属沉积物将通过经经济验证的生物湿法冶金方法转化为廉价的混合金属催化剂，用于在THAI工艺中进行测试。利用纳米颗粒催化剂的有效性的关键在于使它们与发生反应的移动的油区和油井火焰前沿中的油接触的能力。将使用X射线显微断层摄影术等技术对岩石空隙结构进行研究。蒙特卡罗和格子玻尔兹曼模拟将用于研究颗粒气动输送到储层中，并研究岩石空隙空间内颗粒的渗透和分布。浆液催化剂的输送和工艺性能将使用STARS油藏模拟软件进行建模。不同催化剂的评价将在真实的条件下使用根据先前项目开发的钻机进行实验。将通过实验研究气油比、温度、压力和气体成分等变量的影响，以选择最佳催化剂并了解最大程度升级所需的条件。这些实验还将表明在使用过程中是否发生催化剂失活，并使条件能够调整以避免失活。

Extensive unexploited resources of heavy oil and bitumen exist, for example in Canada and Venezuela, as well as heavier deposits under the North Sea UK, which could potentially be utilized as the production of conventional light crude declines. Heavy oil and bitumen are more difficult to recover than conventional crude, requiring mining or specialized in-situ recovery techniques followed by upgrading to make them suitable for use as a fuel. Toe to heel air injection (THAITM) is an in-situ combustion and upgrading process in which air is injected to a horizontal well to feed combustion of a small fraction of the oil (up to 15 %). The heat generated causes the oil to flow along the well, where thermal upgrading reactions occur, leading to upgrading of the oil (by 4-6 API). CAPRI is a catalytic add-on to THAI in which catalyst is packed around the well to effect further catalytic upgrading reactions, such as hydrotreatment, however previous studies showed that the catalyst lifetime and process effectiveness are limited by coke deposition upon the catalyst. Additionally the costs and challenges of packing the well with pelleted catalyst prior to starting up also make the CAPRI process less economically attractive.The current proposal seeks to develop cheap, effective nanoparticulate catalysts which could be conveyed into the well by air or as slurry during operation, thereby avoiding the requirement for packing the well with catalyst prior to start up and to reduce the amount of deactivation and bed blockage that occurs by coke deposition upon pelleted catalysts. Initially, readily available iron oxide nanoparticles will be tested as a base-case. Nanoparticulate catalysts will also be prepared by supporting the metal upon bacteria, using a method in which metal containing solution is reduced in the presence of a bacterial culture, followed by centrifuge and drying which kills the live bacteria. The method has the advantages of being able to utilize scrap metal solutions and thus facilitate recycling of metals from waste sources, and it may be tuned to engineer nanoparticles of desired size and properties (e.g. crystal structures). Here we seek to develop, test and scale up the production of biogenic Fe catalysts for the upgrading of oil in the THAI process. Furthermore, waste road dusts contain deposits of catalytic metals from the exhaust of vehicular catalytic converters and these will be converted into cheap mixed metal catalysts by economically proven biohydrometallurgical methods for testing in the THAI process.Key to the effectiveness of utilizing nanoparticle catalysts will be the ability to contact them with oil in the mobile oil zone and flame front of the well, where the reaction is taking place. Studies of the rock void structure will be carried out using techniques such as X-Ray microtomography. Monte Carlo and Lattice Boltzmann simulations will be used to study the pneumatic conveying of particles into the reservoir and to study penetration and distribution of particles within the void space of the rocks. Conveying of slurry catalysts and process performance will be modeled using STARS reservoir simulation software.Evaluation of the different catalysts will be performed experimentally under real conditions using a rig developed under a previous project. The effect of variables such as gas:oil ratio, temperature, pressure and gas composition will be studied experimentally, in order to select the best catalyst and understand the conditions required for maximum upgrading. The experiments will also indicate whether catalyst deactivation occurs during use and enable conditions to be tuned to avoid deactivation.