Proposal On Horizontal Directional Drilling Research Thesis [PDF]

Citation preview

RESEARCH PROGRAMME This research programme shall study how pipelines can be installed across obstacles such as water courses by the use of horizontal directional drilling, rather than the conventional opentrench method. STUDY BACKGROUND Horizontal Directional Drilling (HDD) involves the application of techniques and equipments that are used in horizontal oil well drilling [and conventional road boring] to install pipelines underground, especially in sensitive areas. This is achieved in three (3) stages: drilling of a pilothole from an entry point to an exit point, reaming of the pilot-hole to achieve the desired hole diameter, and the installation of the pipeline into the hole via pulling back. Although there are other methods of crossing pipelines through obstacles, HDD has proven to be the most efficient, reliable and of minimal environmental impact as compared to others. The future of HDD depends so much on researches and developments in oil well directional drilling. This project shall examine the HDD process and its feasibility assessment. It shall also use a case study to make comparison between HDD and the conventional open earth method and then discuss their applicabilities. The project shall examine the various issues and challenges facing the use of HDD in Nigeria. It shall also identify and propose a number of areas where the use of HDD can be improved through a more realistic consideration of drilling fluid properties, and better designing of drill path and the use of protective casing to overcome frac-out (hydraulic fracturing of the formation by drilling mud) potentials especially in the Niger Delta region where soils usually have high vertical permeability.



TECHNICAL OBJECTIVES: The purpose of the work includes: 



To give a general overview of HDD with emphasis on drill path design.







To make comparison between HDD and open-trench pipeline installation methods in terms of economics and environmental impact assessment.







To identify the various challenges facing the use of HDD in Nigeria.







To study the various factors that contributes to the hydraulic fracturing of the soil, the areas where it is likely to occur and the environmental implications.







To examine the drilling fluid considerations in designing of engineered HDD installations.







To study the soil-pipeline interaction and capstan effect due to the degree of curvature of hole, during the pull-back stage of an HDD project.



EXPECTED OUTCOME: It is expected that at the end of the project, we would be able to: 



Know what HDD is and what it entails; from pre-site planning to installation.







Know the limitations and advantages of HDD over the open-trench method.







Know the various factors that contributes to frac-out during HDD project implementaion.







Know how to design drill path to reduce the potential for frac-out.







Know how protective casing can be used to reduce the possibility of frac-out occurrence, and also to ensure mud returns.







Know how annular pressure curve can be constructed from existing records for prediction of frac-out.







Understand the drilling mud formulation and rheological property that can guarantee a successful engineered HDD installation.







Know how frac-out can be contained in case it occurs.







Know how inadvertent mud release can be prevented, detected, contained and remedied.



METHODOLOGY: The research method to be used shall include field data gathering, imputation & analysis [including the use of Inrock drilling software] , and review of relevant literature for investigation. The field data in the work shall include but is not limited to: o Diameter of pipeline o Length of crossing o Entry and exit angles o Radius of curvature of hole o Depth of cover o Diameter of Hole o Diameter of drill pipe o



Diameter of reamers



o



Drilling mud rheological properties and composition



o Soil type.



DATA REQUIRED: Raw field data shall be obtained from several HDD projects carried out in the Niger Delta region by an HDD company X, and others from already published articles. These data shall include daily drilling report, annular pressure readings, geo-steering data, equipment data, etc.