An Overview of Emerging Technologies and Innovations for Tight Gas Reservoir Development

摘要

As oil prices are significantly increasing in the current decade, oil producers become more and more interested to economically produce natural gas from tight reservoirs. Tight gas reserves represent a huge source of energy that can last for decades. However, the major challenge oil company faces is to find technological solution for economical development and production from such tight reserves. This paper presents a global patent landscape on tight gas recovery technologies. The paper considers the granted patents and patent applications filed from 1990 through today across the globe. The landscape study identifies key patent filers, independent inventores, Universities, and research labs in the area of tight gas recovery technologies. It also identifies different stimulation technologies associated with different patent assignees. Patent lieterature has been used to obtain information on solutions to problems in tight gas recovery areas, such as sweetspot identification, damage minimization, water blocking, and filtrate invasion. Saudi Aramco is seeking suitable partners in recoving tight gas from its vast reserves. The patent filing activity was found to be on an upward trend with filings having increased through the 2000s as compared to during the 1990s. The major contribution to this is from major oil field service providers, such as Schlumberger, Halliburton, Baker Hughes, ExxonMobil, BP and Royal Dutch Shell, with a cumulative share in excess of 50%. Independent inventors (patents which are not assigned to any company/research institute) constituted more than 12% of the total filings. Not to be left behind, academic institutes are also actively filing patents in this area. There are a considerable number of patents filed with joint assignee names, which could be identified through research collaborations, such as Schlumberger and Prad Research and Development; 3M and the University of Texas; MIT and BP. The United States, followed by Canada and the European Patent Office (EPO), have a maximum number of patent filings while China is the only Asian country to file patents on tight gas formations. Over 50% of the patents filed have been made through the Patent Cooperation Treaty (PCT) route indicating the assignees' intent to practice these technologies globally. Schlumberger is a key player in the tight gas recovery area focusing on hydraulic fracturing and slick water fracturing. The patents disclosed by these companies disclose acid fracturing in addition to hydraulic fracturing. ExxonMobil has also filed a patent each on multistage fracturing and thermal fracturing, in addition to hydraulic fracturing. Halliburton and Baker Hughes also focus mainly on hydraulic fracturing. Baker Hughes has one patent on slick water fracturing and one patent on acid fracturing, while Halliburton has one patent on foam fracturing.