О геодинамической устойчивости и безопасности объектов обустройства месторождений прибрежного шельфа Арктики

Abstract

The article considers a range of the scientific and technical problems, the solution of which will allow to improve the reliability and safety of the offshore oil and gas production, since the current level of technical means development for drilling wells and hydrocarbon production does not always guarantee the safety of processes even in well-studied onshore conditions. Safe development of the offshore oil and gas fields is threatened by: hazardous phenomena and processes in the geological environment (including endogenous and exogenous processes); extreme hydrometeorological factors; errors at all stages of the development (engineering surveys, design, construction, etc.); abnormal technological processes; technogenic hazards, etc. The least predictable are the spatial patterns of changes in the engineering-geological conditions and the activity of the geological processes to determine zones of the geological hazard. Incorrect conclusions of the designers and prospectors, shortcomings of the monitoring system and measures of engineering protection of the developed territories are the cause of emergency situations at oil and gas facilities. The article considers three fields of the Yamal Peninsula: Bovanenkovskoye, Kharasaveyskoye and Kruzenshternskoye, which differ from each other in landscape and geocryological conditions. For the onshore Bovanenkovskoye field, the most appropriate is the placement of the objects within the land terraces. The Kharasaveyskoye field, two-thirds of which is onshore and one-third offshore in the Kara Sea, is developed by the onshore directional and horizontal wells. The most difficult are the conditions of the Kruzenshternskoye field: on the shallow shelf and flooded areas of land, there is a wide distribution of silts, flowing clays, etc., which have low strength and strong compressibility extending to an unknown depth. They can lead to significant drawdown of the artificial islands. Permafrost rocks, gas-saturated soils and near-surface zones of abnormally high reservoir pressure were also identified. For the identified conditions, measures are defined to ensure the stability of the geological environment to technogenic interactions, as well as the tasks of developing scientific and methodological control and preventing risks associated with hazardous fluid-dynamic processes in the cryolithospheric layer of the Arctic shelf.