Browsing by Subject "Managed Pressure Drilling"
Now showing 1 - 2 of 2
Results Per Page
Sort Options
Item An Advisory System For Selecting Drilling Technologies and Methods in Tight Gas Reservoirs(2010-01-16) Pilisi, NicolasThe supply and demand situation is crucial for the oil and gas industry during the first half of the 21st century. For the future, we will see two trends going in opposite directions: a decline in discoveries of conventional oil and gas reservoirs and an increase in world energy demand. Therefore, the need to develop and produce unconventional oil and gas resources, which encompass coal-bed methane, gas-shale, tight sands and heavy oil, will be of utmost importance in the coming decades. In the past, large-scale production from tight gas reservoirs occurred only in the U.S. and was boosted by both price incentives and well stimulation technology. A conservative study from Rogner (1997) has shown that tight gas sandstone reservoirs would represent at least over 7,000 trillion cubic feet (Tcf) of natural gas in place worldwide. However, most of the studies such as the ones by the U.S. Geological Survey (U.S.G.S.) and Kuuskraa have focused on assessing the technically recoverable gas resources in the U.S. with numbers ranging between 177 Tcf and 379 Tcf. During the past few decades, gas production from tight sands field developments have taken place all around the world from South America (Argentina), Australia, Asia (China, Indonesia), the Russian Federation, Northern Europe (Germany, Norway) and the Middle East (Oman). However, the U.S. remains the region where the most extensive exploration and production for unconventional gas resources occur. In fact, unconventional gas formations accounted for 43% of natural gas production and tight gas sandstones represented 66% of the total of unconventional resources produced in the U.S. in 2006. As compared to a conventional gas well, a tight gas well will have a very low productivity index and a small drainage area. Therefore, to extract the same amount of natural gas out of the reservoir, many more wells will have to be drilled and stimulated to efficiently develop and produce these reservoirs. Thus, the risk involved is much higher than the development of conventional gas resources and the economics of developing most tight gas reservoirs borders on the margin of profitability. To develop tight gas reservoirs, engineers face complex problems because there is no typical tight gas field. In reality, a wide range of geological and reservoir differences exist for these formations. For instance, a tight gas sandstone reservoir can be shallow or deep, low or high pressure, low or high temperature, bearing continuous (blanket) or lenticular shaped bodies, being naturally fractured, single or multi-layered, and holding contaminants such as CO2 and H2S which all combined increase considerably the complexity of how to drill a well. Since the first tight gas wells were drilled in the 1940's in the U.S., a considerable amount of information has been collected and documented within the industry literature. The main objective of this research project is to develop a computer program dedicated to applying the drilling technologies and methods selection for drilling tight gas sandstone formations that have been documented as best practices in the petroleum literature.Item Managed Pressure Drilling Candidate Selection(2010-07-14) Nauduri, Anantha S.Managed Pressure Drilling now at the pinnacle of the 'Oil Well Drilling' evolution tree, has itself been coined in 2003. It is an umbrella term for a few new drilling techniques and some preexisting drilling techniques, all of them aiming to solve several drilling problems, including non-productive time and/or drilling flat time issues. These techniques, now sub-classifications of Managed Pressure Drilling, are referred to as 'Variations' and 'Methods' of Managed Pressure Drilling. Although using Managed Pressure Drilling for drilling wells has several benefits, not all wells that seem a potential candidate for Managed Pressure Drilling, need Managed Pressure Drilling. The drilling industry has numerous simulators and software models to perform drilling hydraulics calculations and simulations. Most of them are designed for conventional well hydraulics, while some can perform Underbalanced Drilling calculations, and a select few can perform Managed Pressure Drilling calculations. Most of the few available Managed Pressure Drilling models are modified Underbalanced Drilling versions that fit Managed Pressure Drilling needs. However, none of them focus on Managed Pressure Drilling and its candidate selection alone. An 'Managed Pressure Drilling Candidate Selection Model and software' that can act as a preliminary screen to determine the utility of Managed Pressure Drilling for potential candidate wells are developed as a part of this research dissertation. The model and a flow diagram identify the key steps in candidate selection. The software performs the basic hydraulic calculations and provides useful results in the form of tables, plots and graphs that would help in making better engineering decisions. An additional Managed Pressure Drilling worldwide wells database with basic information on a few Managed Pressure Drilling projects has also been compiled that can act as a basic guide on the Managed Pressure Drilling variation and project frequencies and aid in Managed Pressure Drilling candidate selection.