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Three primary horizontal methane drainage holes totaling 2,428.4 meters (7,967 feet) have been completed in the Pittsburgh coalbed from a directional surface borehole. Directional control and sidetracking techniques developed during the project increased the horizontal drilling rate from 24.4 meters (80 feet) per day initially to 64.9 meters (213 feet) per day on the third horizontal hole. Drilling data indicate that horizontal holes can be drilled substantially longer than the maximum 977 meters (3,207 feet) achieved.
Horizontal drilling required approximately 15 years to evolve into a mature technology. During this time, the petroleum industry witnessed amazing feats of extended-reach technology, updip horizontal drilling, rotary-steerable technology, and now directional drilling with casing. Horizontal drilling became feasible in the 1980s with the emergence of measurement-while-drilling downhole survey tools. Horizontal drilling continues to be a powerful application for exposing more reservoir per motherbore (multilaterals), increasing productivity from tight rock, acquiring exposure to multiple subsurface compartments, producing heavy-oil reservoirs (with steam-assisted gravity drainage), and managing waterdrive reservoirs. It is a particularly strong application in clean sandstones with low-vertical-permeability barriers. However, horizontal drilling also can address thin-layered petroleum traps with poor-to-low horizontal permeability. Horizontal completions are limited only by the imaginations of those who drill horizontally. There soon will be a day when one builds a curve considerably below the level of the lateral and places a subsurface pump below the level of production. How many of Earth's petroleum reservoirs are shallow, have no reservoir pressure, cannot be drilled vertically economically, and yet will respond to gravity drainage in a horizontal wellbore? Horizontal and Complex-Trajectory Wells additional reading available at the SPE eLibrary: IPTC 10966 "Reservoir-Screening Methodology for Horizontal Underbalanced-Drilling Candidacy" by T. van der Werken, SPE, Weatherford, et al. SPE 102678 "Analyzing Under performance of Tortuous Horizontal Wells: Validation With Field Data" by M. Kerem, SPE, Shell Intl. E&P B.V., et al. SPE 101129 "Development of Small- and Medium-Sized Oil Fields Through Horizontal Wells—The Way Ahead" by R.D. Tewari, SPE, Greater Nile Petroleum Operating Co., et al. SPE 92804 "Coiled-Tubing Reverse Circulation—An Efficient Method of Cleaning Horizontal Wells in a Mature Pressure-Depleted Field" by P. Santhana Kumar, SPE, Petroleum Development Oman, et al.
Abstract Nigeria pipelines especially the petroleum and petroleum product pipelines are always vandalized by the sabotage. Huge amount of money is expended to put the damaged pipeline in good shape, and petroleum and petroleum product transfer is sometimes hampered due to leakages and damages caused by the oil thieves. Also huge money is being budgeted yearly to secure the pipelines. To combat this problem, Horizontal Directional Drilling (HDD) is being proposed. HDD is a method of installing underground pipes and conduits along a prescribed bore path from the surface, with minimal impact to the surrounding area. Installation lengths up to 6500ft and depth of 200ft have been completed and diameters up to 48 in. have been installed in shorter runs. The process begins when a directional bore machine pushes a bore head connected to hollow pipe into the ground at an angle. As each joint of drill pipe is pushed into the ground a new one is added behind. In rock, a mud motor, which converts the hydraulic pressure of the drilling fluid into mechanical rotation, is used to rotate the bit and the drill pipe is not continuously rotated. Steerage is accomplished by aligning the angle of the mud motor to the desired direction. This paper investigates the challenges and prospects of using the HDD technique to lay pipeline to a greater depth/distance that will be inaccessible by the oil thieves. The construction process (pilot hole, reaming and pullback) along with the major components (drill rig, drill pipe, slurry, slurry recycling, survey equipment, drill bits, and reamers) is discussed. The advantages of cost reduction, and environmental, social and time benefits were examined in this study. The challenges of proper soils information, subsurface conditions, training and knowledge, drilling fluids and binding of the drill pipe and reamer/bit are highlighted.
Directional drilling techniques have been used for many years to reach subsurface objectives that have had inaccessible surface locations. Economic considerations and increased environmental concerns have increased the number of directional wells drilled in recent years. Directional drilling techniques have also been applied to horizontal drilling with interest in this area increasing greatly over the last several years.
In the past, there have been two major methods utilized in planning the directional well. These methods are the use of planning the directional well. These methods are the use of buildup or composite buildup charts and the use of several directional well planning equations, each method depending on the particular wellbore geometry desired. The use of buildup charts is particular wellbore geometry desired. The use of buildup charts is a tedious process that often yields inaccurate results since it requires using preplotted graphs that require interpretation and interpolation. The equation approach is often confusing to use due to the similarity of the various equations with the selection of the proper equation dependent on the desired wellbore geometry.
This paper presents the derivation of a single equation for planning the trajectory of any directional well and a similar planning the trajectory of any directional well and a similar equation for any horizontal well. Several examples are used to demonstrate the application of the equations to various wellbore geometries.
Directional drilling is the purposeful deflection of a wellbore from the vertical along some preplanned trajectory to a predetermined target. The necessity of directional drilling is usually dictated by economic and environmental concerns. Applications for directional drilling are varied with the most common application of directional drilling techniques probably being in offshore waters. Here, several wells are drilled from a single platform to different bottomhole locations, allowing the optimization of development costs. Similarly, directional wells have been drilled in remote areas from artificial islands and drilling pads. This type of operation is common in places like Alaska, the Canadian Arctic and the jungle areas of South America. Drilling multiple wells from a single location can greatly simplify the installation of gathering and production facilities.
Inaccessible surface locations also require the use of directional drilling techniques. The inaccessibility may be the result of natural barriers, such as rivers, lakes and mountainous terrain, or man-made barriers, like highways and populated areas. In these situations, single wells may be directionally drilled to reach the objective target. Directional drilling techniques are also used in drilling relief wells, drilling in saltdome areas and in some fishing operations.
Another and rapidly growing area requiring directional drilling techniques is horizontal and extended reach drilling. Generally, horizontal wells are drilled for economic reasons. Applications include consolidated, naturally fractured reservoirs where the wellbore may intersect multiple fracture systems. They have also been drilled to reduce coning problems in reservoirs that have large gas caps or strong water drives. In some reservoirs the horizontal well may improve drainage by increasing the area of the wellbore in contact with the reservoir.
Deflecting a wellbore involves many factors which must be considered individually. As a result, careful planning is the key to successful directional drilling. One of the first steps in planning the directional well should be the design of the wellbore planning the directional well should be the design of the wellbore trajectory. Wellbore trajectories can be categorized into two classes, the directional well and the horizontal well.
In the directional well class, there are three basic types of wellbore geometries: Type I, Type II and Type III. Fig. 1 shows these major types of wellbore configurations. A Type I well is basically a "build and hold" trajectory where the wellbore is deflected from the vertical at some kickoff point and the angle built until a maximum angle is reached and then held until the target is intercepted by the wellbore. A Type II well is a "build, hold and drop" or "S" trajectory where the wellbore is deflected to some angle, the angle is held and then dropped in a manner such that the target is penetrated vertically. A modified Type II well differs in that the wellbore is not returned to the vertical in the drop portion.
World Longest Expandable However, horizontal technology proliferated with the advent of measurement-whiledrilling Openhole Clad and Openhole techniques and mud-pulse telemetry in the mid-1980s. The ability to survey Liner With Swelling Elastomer without major drilling downtime made downhole steering an economic reality. Economic Deployed in Yibal Horizontal viability and reliable horizontal-drilling tools gained acceptance, and strong application Well engineering began to emerge in the late 1980s and early 1990s. Following the initial success was a myriad of challenges, including completing a horizontal wellbore and determining - SPE 89755 the effect of the completion on the reservoir. Production Strategy for Thin Oil Columns in Saturated Today, horizontal technology--with the assistance of sound completion engineering-- Reservoirs has been shown to improve the ultimate recovery of reserves.