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The petroleum industry is in a constant state of change. Few industries have advanced as far technologically as the petroleum industry has in its relatively brief existence. The produced products in the oil and gas industry are finite. As such, the easier to find and produce hydrocarbons are exploited first. This forces the industry to enter new areas and environments to continue supplying the world's hydrocarbons. Many of these new frontiers are in what is considered ultradeep waters, 5000 feet or more of water. While all areas of the oil and gas industry have advanced their ultradeep water technology, one area has had to remain at the forefront: drilling. Unfortunately, while drilling as a whole may be advancing to keep up with these environments, some segments lag behind. Blowout control is one of these areas developed as an afterthought. This lax attitude towards blowouts does not mean they are not a major concern. A blowout can mean injury or loss of life for rig personnel, as well as large economic losses, environmental damage and damage to the oil or gas reservoir itself. Obviously, up-to-date technology and techniques for the prevention and control of ultradeep water blowouts would be an invaluable part of any oil and gas company's exploration planning and technology suite. To further the development of blowout prevention and control, COMASim Cherokee Offshore, MMS, Texas A&M Simulator) was developed. COMASim simulates the planning and execution of a dynamic kill delivered to a blowout. Through a series of over 800 simulation runs, we were able to find several key trends in both the initial conditions as well as the kill requirements. The final phase of this study included a brief review of current industry deepwater well control best practices and how the COMASim results fit in with them. Overall, this study resulted in a better understanding of ultradeep water blowouts and what takes to control them dynamically. In addition to this understanding of blowouts, COMASim's strengths and weaknesses have now been exposed in order to further develop this simulator for industry use.

Horizontal directional drilling (HDD) has been employed in many situations including cable lines under rivers and rehabilitation of pipelines under buildings and busy traffic. Within the context of a municipal landfill site, a by-product of organic waste (leachate) accumulates within an established landfill. Leachate is a liquid produced from the wastes placed inside landfills and rain that percolates through the wastes and reacts with the products of decomposition. This thesis investigates the effectiveness of employing HDD techniques to extract leachate in the municipal landfill application.

Horizontal directional drilling (HDD) has been employed in many situations including cable lines under rivers and rehabilitation of pipelines under buildings and busy traffic. Within the context of a municipal landfill site, a by-product of organic waste (leachate) accumulates within an established landfill. Leachate is a liquid produced from the wastes placed inside landfills and rain that percolates through the wastes and reacts with the products of decomposition. This thesis investigates the effectiveness of employing HDD techniques to extract leachate in the municipal landfill application.

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.

The purpose of this study is to determine the feasibility of replacing diesel with natural gas as a fuel source for modern drilling rigs. More specifically, this thesis (1) establishes a control baseline by examining operational characteristics (response, fuel usage, and cost) of an existing diesel-powered land rig during the drilling of a well in the Haynesville Shale; (2) estimates operational characteristics of a natural gas engine under identical conditions; and (3) draws a comparison between diesel and natural gas engines, determining the advantages and disadvantages of those fuel sources in drilling applications. Results suggest that diesel engines respond to transient loads very effectively because of their inherently higher torque, especially when compared with natural gas engines of a similar power rating. Regarding fuel consumption, the engines running on diesel for this study were more efficient than on natural gas. On a per-Btu basis, the natural gas engines consumed nearly twice as much energy in drilling the same well. However, because of the low price of natural gas, the total cost of fuel to drill the well was lowered by approximately 54%, or 37,000 USD. Based on the results, it is possible to infer that the use of natural gas engines in drilling environments is feasible, and in most cases, an economical and environmental advantage. First, when compared with diesel, natural gas is a cleaner fuel with less negative impact on the environment. Second, fuel cost can be reduced by approximately half with a natural gas engine. On the other hand, natural gas as a fuel becomes less practical because of challenges associated with transporting and storing a gas. In fact, this difficulty is the main obstacle for the use of natural gas in drilling environments. In conclusion, because of its minimal drawback on operations, it is recommended that in situations where natural gas is readily available near current market prices, natural gas engines should be utilized because of the cost savings and reduced environmental impact. In all other cases, particularly where transport and storage costs encroach on the cost benefit, it may still be advantageous to continue powering rigs with diesel because of its ease of use.

The extreme operating conditions in deepwater drilling lead to serious relative problems. The knowledge of subsea temperatures is of prime interest to petroleum engineers and geo-technologists alike. Petroleum engineers are interested in subsea temperatures to better understand geo-mechanisms; such as diagenesis of sediments, formation of hydrocarbons, genesis and emplacement of magmatic formation of mineral deposits, and crustal deformations. Petroleum engineers are interested in studies of subsurface heat flows. The knowledge of subsurface temperature to properly design the drilling and completion programs and to facilitate accurate log interpretation is necessary. For petroleum engineers, this knowledge is valuable in the proper exploitation of hydrocarbon resources. This research analyzed the thermal process in drilling or completion process. The research presented two analytical methods to determine temperature profile for onshore drilling and numerical methods for offshore drilling during circulating fluid down the drillstring and for the annulus. Finite difference discretization was also introduced to predict the temperature for steady-state in conventional riser drilling and riserless drilling. This research provided a powerful tool for the thermal analysis of wellbore and rheology design of fluid with Visual Basic and Matlab simulators.

Dual Gradient Drilling (DGD) system is a promising technology that was developed to overcome the deep water drilling problems occurred due to narrow operating window between pore pressure and fracture pressure. In conventional drilling practice, single mud weight exists from drilling unit to TVD (True Vertical Depth) which creates big hydrostatic pressure in bottom hole ,moreover, minor changes in mud weight results a big pressure changes proportional to the length of hydrostatic column increase with water depth. On the other hand, DGD allows using two different mud weights to get same bottom hole pressure / low gradient drilling fluid from drilling unit to the sea floor and high gradient drilling fluid form the sea floor to TVD, to decrease the effect of water column on mud hydrostatic pressure in TVD. In this thesis, a conventionally drilled deepwater well was redesigned considering the DGD system and drilled virtually to determine the changes of cost of services and materials on total operation budget to prove the positive impact of system on total operation cost. This study not only proved the technical advantages of the DGD system, but also showed economical impact of the system on total drilling cost, by decreasing around 19%.

Well control is of the utmost importance during drilling operations. Numerous well control incidents occur on land and offshore rigs. The consequences of a loss in well control can be devastating. Hydrocarbon reservoirs and facilities may be damaged, costing millions of dollars. Substantial damage to the environment may also result. The greatest risk, however, is the threat to human life. As technology advances, wells are drilled to greater distances with more complex geometries. This includes multilateral and extended-reach horizontal wells. In wells with inclinations greater than horizontal or horizontal wells with washouts, buoyancy forces may trap kick gas in the wellbore. The trapped gas creates a greater degree of uncertainty regarding well control procedures, which if not handled correctly can result in a greater kick influx or loss of well control. For this study, a three-phase multiphase flow simulator was used to evaluate the interaction between a gas kick and circulating fluid. An extensive simulation study covering a wide range of variables led to the development of a best-practice kick circulation procedure for multilateral and extended-reach horizontal wells. The simulation runs showed that for inclinations greater than horizontal, removing the gas influx from the wellbore became increasingly difficult and impractical for some geometries. The higher the inclination, the more pronounced this effect. The study also showed the effect of annular area on influx removal. As annular area increased, higher circulation rates are needed to obtain the needed annular velocity for efficient kick removal. For water as a circulating fluid, an annular velocity of 3.4 ft/sec is recommended. Fluids with higher effective viscosities provided more efficient kick displacement. For a given geometry, a viscous fluid could remove a gas influx at a lower rate than water. Increased fluid density slightly increases kick removal, but higher effective viscosity was the overriding parameter. Bubble, slug, and stratified flow are all present in the kick-removal process. Bubble and slug flow proved to be the most efficient at displacing the kick.

The petroleum industry is in a constant state of change. Few industries have advanced as far technologically as the petroleum industry has in its relatively brief existence. The produced products in the oil and gas industry are finite. As such, the easier to find and produce hydrocarbons are exploited first. This forces the industry to enter new areas and environments to continue supplying the world's hydrocarbons. Many of these new frontiers are in what is considered ultradeep waters, 5000 feet or more of water. While all areas of the oil and gas industry have advanced their ultradeep water technology, one area has had to remain at the forefront: drilling. Unfortunately, while drilling as a whole may be advancing to keep up with these environments, some segments lag behind. Blowout control is one of these areas developed as an afterthought. This lax attitude towards blowouts does not mean they are not a major concern. A blowout can mean injury or loss of life for rig personnel, as well as large economic losses, environmental damage and damage to the oil or gas reservoir itself. Obviously, up-to-date technology and techniques for the prevention and control of ultradeep water blowouts would be an invaluable part of any oil and gas company's exploration planning and technology suite. To further the development of blowout prevention and control, COMASim Cherokee Offshore, MMS, Texas A&M Simulator) was developed. COMASim simulates the planning and execution of a dynamic kill delivered to a blowout. Through a series of over 800 simulation runs, we were able to find several key trends in both the initial conditions as well as the kill requirements. The final phase of this study included a brief review of current industry deepwater well control best practices and how the COMASim results fit in with them. Overall, this study resulted in a better understanding of ultradeep water blowouts and what takes to control them dynamically. In addition to this understanding of blowouts, COMASim's strengths and weaknesses have now been exposed in order to further develop this simulator for industry use.