Rich deposits of natural gas and ways for carrying hydrocarbons have become the apple of discord among world energy corporations, giving latent causes for dangerous political demarches and international conflicts. Increasingly, these tendencies are becoming noticeable in view of a lack of easily accessible oil and gas resources.
According to forecasts by the Club of Rome, the reserves of the traditional deposits of hydrocarbons will be exhausted by the end of the 21st century. Current data from ВР Statistical Review show that if development of gas continues at the rates of 2015, its world reserves are supposed to suffice for 52 years and six months. Worthwhile development of energy mineral resources is mostly connected with the innovative technologies of development of shale gas and methane crystal hydrates in the Ocean.
Aggregate reserves of methane gas hydrates exceed considerably prospected conventional reserves of natural gas and are seen as the most powerful source of potential mineral energy resources. If the present-day world consumption of gas remains unchanged, the reserves of methane bottom gas hydrates will suffice for mankind’s needs for several centuries, provided a ‘technological clue’ to their production is discovered. At present, only a part of these formations concentrated along coastland of continents can be considered as potentially commercial reserves. Given the magnitude and prospects of the offshore production of minerals, the Ocean has become ‘space No. 1’ for the mankind by the amount of research, engineering developments and capital investments over the last decade, the above indicators relegating significantly near-earth space programs to the sidelines.
The problem of Ukraine’s energy security is closely connected with an increase in gas production at Ukrainian deposits, which could involve prospected formations of bottom gas hydrates in the Black Sea. According to forecasts, the resources of methane that occur in the formations of gas hydrates near the Crimea alone are estimated at from 20 trillion to 25 trillion cubic meters (reserves in the Black Sea formations total 45–60 trillion cubic meters). While the government of Ukraine approved the program “Gas Hydrates in the Black Sea” in late 1993, an economic recession in the 1990s and latent influence of the suppliers of gas to Ukraine became a brake on planned research and project activities. Ukrainian and German researchers have organized four offshore expeditions from 2002 through 2011 that proved the existence of formations, obtained the first samples of gas hydrates, analyzed the content of extracted gas mixtures and the conditions of the development of formations. Although detailed research on prospective exploitation areas in this country is only at an initial stage, it confirms the high potential of Ukraine’s formations of gas hydrates.
The crucial problem of the successful development of offshore fields is to create the efficient and reliable technology of methane production. Many countries adopted national programs for research on methane hydrates. In 2000 the U.S. Congress had approved the Methane Hydrate Research and Development Act. In 2013 Japan had successfully extracted industrial gas from frozen methane hydrate that is the world’s first offshore experiment producing gas from methane hydrate. Nevertheless, the economically viable technology of the development of the formations of methane hydrates has not been created yet. Moreover, the greater part of offshore fields cannot be developed at all, given the present-day technical situation. This requires the development and approbation of new scientific ideas, methodological recommendations, constructive and technological concepts to establish the wide innovative environment, which would generate solutions to the problem of gas hydrates.
Incidentally, a group of researchers led by Prof. Gennady Gaiko of the Kiev Polytechnic Institute (KPI) have the intriguing concept that provides for practice of a wide-ranging impact on the vast area of the bedding plane or internal structure of a gas hydrate deposit. However, the main idea lies in the formation of the open system of fissures in rocks of the roof of a gas hydrate layer. Released gas flows out through the system to a big gas-collecting blanket that shields the greater part of the bedding plane of a formation.
The proposed techniques of gas production from bottom gas hydrates uncover a new concept of the shielded development of deposits that changes the established approaches to local impacts on a productive layer. Although one of the traditional physicochemical techniques of the development of minerals, namely the well-drilling technology, is seen by the authors as the reliable tool of the dissociation of the vast areas of gas hydrate deposits, it cannot serve at the same time as the efficient tool of the recovery and transportation of released methane. That is why it is worth focusing on an alternative way. What researchers have been always attempting (a priori unsuccessfully) to prevent, namely the penetration of released methane in a water area, should be the target of the main phase of a development technique, making this process manageable and sustainable. The preparatory phase should involve the making of a gas-collecting shield from the elastic blankets that cover the vast areas of a bottom surface above a deposit, collect and accumulate the released methane of a gas hydrate formation. Further, the technique provides for the sustainable removal of recovered gas from several blankets to a bottom pipeline, and the transportation of methane to a coastal gas-distributing station and consumers.
The features of a new approach include the simultaneous dissociation of gas hydrate in the vast area of a gas hydrate deposit and the sustainable removal of the aggregately considerable (sufficient for competitive commercial development) amounts of methane without the threat of an explosive effect. The considerable saving of resources is due to the unmanned technique of the exploitation of a deposit (all expenses and labor resources are concentrated at the preparatory phase of assembling of equipment), as well as to the non-use of highly cost-intensive seagoing ships and offshore platforms during the production of methane.
Elaboration and substantiation of the conditions for the technique of the shielded development of gas hydrate formations may well open up new vistas for the development of Ukrainian and world marine gas hydrate formations.
Currently, the KPI researchers are working on 1) the techniques of washout, explosive destruction and fracking of rocks of the roof; 2) facilities designed for gas dissociation through depressurization, injection of a heat carrier or chemical reagent; 3) design and technology of assembling large gas-collecting shields; 4) system of transportation of gas obtained from a gas-collecting shield through sea-bed pipelines in particular.
The system of shielded development of gas hydrate formations may well become the unique technique of methane production that would require a broad synergy of efforts among concerned partners and investors. The KPI scientists invite all the parties concerned to cooperate on the project with them.
Additional information: ogo55@ukr.net
THE UKRAINIAN TIMES 