Directional drilling has become a popular construction method used by municipalities, contractors and engineers alike for the construction of new subsurface pipelines while minimizing impact on the surrounding community. Pressurized drilling fluid is used during the advancement of the borehole through granular materials to maintain borehole stability throughout the drill path. It is believed that failure of the soil surrounding the borehole is controlled by the shear strength of this frictional ground and this influences the maximum allowable mud pressure that may be applied to the borehole. While there have been a number of theoretical studies, there have been few if any experimental investigations to examine the efficacy of the proposed design equations. The basis of this research considers a horizontal directionally drilled borehole and compares the analytical findings with those obtained from a series of smaller and larger-scale laboratory experiments for a uniformly graded sand and layered sand - sand and gravel case. The analytical solutions are considered reasonable for hydrofracture during pullback, but may not be directly applicable to blowout during pilot borehole drilling such as the model researched in the experiments. During the experiments the downhole mud pressures were continuously monitored and observations of composite drilling fluid and sand material were made. Smaller-scale experiments were carried out to determine the response of the horizontal stresses resulting from internal pressurization acting on the sidewalls of the test cell. During the larger-scale experiments, the surface displacements were measured to better understand the influence of an increase in the soil volume with surface displacement. iii Through the course of the research, physical information has been collected regarding the changes that a clean sand undergoes when in contact with a drilling fluid, the ability of a borehole to resist internal loading, and the effectiveness of the various analytical models currently used to estimate the peak allowable internal fluid pressures. In addition, physical data has been collected regarding the displacement of a surrounding material during the introduction of drilling fluid into a horizontally drilled borehole / Thesis (Master, Civil Engineering) -- Queen's University, 2008-07-25 14:16:41.951

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.

Thesis (Ph.D.)--University of Tulsa, 1995. / Includes bibliographical references (leaves 67-70).

Thesis (Ph.D.)--University of Tulsa, 1987. / Page xv lacking. Bibliography: leaves 150-154.

Thesis (M. Sc.)--University of Hong Kong, 2003. / Also available in print.

Thesis (Ph.D.)--University of Tulsa, 1986. / Bibliography: l. 104-116.

The aim of this study is to combine the basic concepts of mechanics on drill string which are related to directional drilling, thus finding a less complicated and more economical way for drilling directional wells. Slick BHA, which has no stabilizers attached and single stabilizer BHA are analyzed through previously derived formulas gathered from the literature that are rearranged for this study. An actual directional well is redrilled theoretically with a slick BHA and a computer program is assembled for calculating the side force and direction of the well for single stabilizer BHA. Influence of controllable variables on drilling tendency is investigated and reported. The study will be useful for well trajectory and drill string design in accordance with the drilling phase. Also, by using available data from offset wells, drilling engineer can back-calculate the formation anisotropy index (FAI) that is often used for optimizing well trajectories and predicting drilling tendency on new wells in similar drilling conditions. After analysing the directional well data used in this study, it has been concluded that the well could be drilled without a steerable tool if the kick of point (KOP) is not a shallower depth. If the KOP is kept similar, the same curvature could not be achieved without a steerable tool.

The world is dependent on the production of oil and gas, and every day the demand increases. Technologies have to keep up with the demand of this resource to keep the world running. Since hydrocarbons are finite and will eventually run out, the increasing demand of oil and gas is the impetus to search for oil in more difficult and challenging areas. One challenging area is offshore in ultradeep water, with water depths greater than 5000 ft. This is the new arena for drilling technology. Unfortunately with greater challenges there are greater risks of losing control and blowing out a well. A dynamic kill simulator was developed in late 2004 to model initial conditions of a blowout in ultradeep water and to calculate the minimum kill rate required to kill a blowing well using the dynamic kill method. The simulator was simple and efficient, but had limitations; only vertical wells could be simulated. To keep up with technology, modifications were made to the simulator to model directional wells. COMASim (Cherokee, Offshore Technology Research Center, Minerals Management Service, Texas A&M Simulator) is the name of the dynamic kill simulator. The new version, COMASim1.0, has the ability to model almost any type of wellbore geometry when provided the measured and vertical depths of the well. Eighteen models with varying wellbore geometry were simulated to examine the effects of wellbore geometry on the minimum kill rate requirement. The main observation was that lower kill rate requirement was needed in wells with larger measured depth. COMASim 1.0 cannot determine whether the inputs provided by the user are practical; COMASim 1.0 can only determine if the inputs are incorrect, inconsistent or cannot be computed. If unreasonable drilling scenarios are input, unreasonable outputs will result. COMASim1.0 adds greater functionality to the previous version while maintaining the original framework and simplicity of calculations and usage.

Since the 1980’s horizontal drilling has been a game-changing technology as it allowed the oil and gas industry to produce from reservoirs previously considered marginal or uneconomic. However, while it is considered a mature technology, directional drilling is still done in a reactive fashion. Although many directional drillers are quite adept at predicting the directional response of the bottomhole assembly (BHA) in a given well, the ability to manage all of the drilling parameters on a foot by foot basis while accurately predicting the effects of each parameter is impossible for the human brain alone. Given current rig rates, any amount of increased slide time and its reduced ROP which occurred due to poorly predicted directional response can result in a significant economic impact. There exist many measured parameters or system inputs which have been proven to affect the directional response of a drilling system. One parameter whose effect has not been investigated is mechanical specific energy or MSE. MSE is measure of how efficient the drilling process is in relation to rate of penetration. To date, MSE has primarily been used with for vibration analysis and rate of penetration optimization. The following dissertation covers research into the effect of MSE on the overall wellbore direction change or dog-leg severity. Using published experimental data, a correlation was developed which shows a clear relationship between the dog-leg severity, rate of penetration (ROP) and MSE. The correlation requires only a few hundred feet of drilling before it is able to be tuned to match an individual well’s results. With minimal tuning throughout the drilling of a well, very good results can be obtained with regards to forecasting dog-leg severity as the wellbores were drilled ahead. The correlation was tested using data from multiple, geo-steered wells drilled in a shale reservoir. The analysis of the correlation using real-world data proved it to be a robust and accurate method of predicting the magnitude of dog-leg severity. The use of this correlation results in a smoother wellbore, drilled with a faster overall ROP with a better chance of staying within the geologic targets.