Optimized Field Development - Shale Gas

Abstract

In the recent decade there have been big changes in the oil and gas industry as the USA have increased their domestic oil and gas production due to shale oil and gas. The production from shale formations has been made possible due to implementation of horizontal drilling and hydraulic fracturing as well as higher prices for oil and gas. As the domestic production in the USA led to an increase in the oil and gas supply to the market, prices have fallen with around 40 % from recent year levels. This has led operators to shut down producing wells because they no longer are profitable. By having projects with short time perspective and lower margins on future production, large amount of resources sit unused in the shale formations which possibly may not be economical to produce in the future. By developing a new field development concept using nitrogen displacement and multilateral technology in North American shale formations as presented in this thesis, the philosophy is to increase and elongate production in order to increase the recovery rates and make better use of the existing resources which in a long run are scarce. A laboratory experiment has been performed to see if existing theories regarding water/oil and gas/oil displacement also are applicable for nitrogen/natural gas (gas/gas) displacement. The tests have been done using a low permeable chalk core plug where changes in density of the flowing gas is measured. The experiment is done by filling and saturating the core with methane and thereafter displacing the methane with nitrogen. In the final parts of the thesis, an economical study has been done in order to see if the project is realistic and to present todays costs of the equipment and facilities needed.