Drilling techniques

If we consider a well trajectory from surface to total depth (TD) it is sensible to look at the shallow section and the intermediate and reservoir intervals separately. The shallow section, usually referred to as top hole consists of rather unconsolidated sediments, hence the formation strength is low and drilling parameters and equipment have to be selected accordingly. 

The reservoir section is more consolidated and is the main objective to which the well is being drilled, hence the drilling process has to ensure that any productive interval is not damaged. 

For the very first section of the borehole a base from which to commence drilling is required. In a land location this will be a cemented cellar in which a conductor or stove pipe will be piled prior to the rig moving in. The cellar will accommodate the Christmas tree (an arrangement of seals and valves), once the well has been completed and the rig has moved off location (Fig. 3.13) 

As in the construction industry, piling of the conductor is done by dropping weights onto the pipe or using a hydraulic hammer until no further penetration occurs. In an offshore environment the conductor is either piled (e.g. on a platform) or a large diameter hole is actually drilled, into which the conductor is lowered and cemented. Once the drill bit has drilled below the conductor the well is said to have been spudded. 

A surface casing is finally cemented to prevent hole collapse and protect shallow aquifers. 

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A mudlog provides only qualitative information, hence it is unsuitable for an accurate formation evaluation. Mudlogging is therefore nowadays partly replaced by logging while drilling techniques (LWD) which will be covered in Section 5.3. 

Whether on land or offshore, the principle of satellite development is the same. A new field is accessed with wells, and an export link is installed to the existing (host) facility. Development is not always easier on land, as environmental restrictions mean that some onshore fields have to be developed using directional drilling techniques (originally associated with offshore developments). A vertical well can be drilled offshore away from the host facility, and the well completed using a subsea wellhead. 

The choice of a particular mining method depends on a number of parameters, typically the physical properties of the host matrix, the fiber content of the ore, the amount of sterile materials, the presence of contaminants, and the extent of potential fiber degradation during the various mining operations (33). However, most of the asbestos mining operations are of the open pit type, using bench drilling techniques. 

In air drilling areas, the use of air drilling technique can be prolonged when formation water enters the hole by adding a small stream of liquid surfactant to the air stream. The addition of surfactant forms foam at the contact with formation water. The foam carries out cuttings and produced water. Considerable volumes of formation water can be held using this technique. 

The lADC Drill Bits Subcommittee began work on a new classification method in 1985. It was determined from the outset that (1) a completely new approach was required, (2) the method must be simple enough to gain widespread acceptance and uniform application, yet provide sufficient detail to be useful, (3) emphasis should be placed on describing the form of the bit, i.e., paint a mental picture of the design , (4) no attempt should be made to describe the function of the bit, i.e., do not link the bit to a particular formation type or drilling technique since relatively little is certain yet about such factors for fixed cutter bits, (5) every bit should have a unique lADC code, and (6) the classification system should be so versatile that it will not be readily obsolete. 

In the United States, air and gas drilling techniques are used extensively in parts of the southwest in and around the San Juan Basin, in parts of the Permian Basin, in Arkansas and eastern Oklahoma, in Maryland, Virginia and parts of Tennessee. Internationally, oil and gas drilling operations are carried out with air and gas drilling techniques in parts of the Middle East, North Africa and in the Western Pacific. 

D. Kinchen, M. A. Peavy, T. Brookey, and D. Rhodes. Case history Drilling techniques used in successful redevelopment of low pressure H2S gas carbonate formation. In Proceedings Volume, volume 1, pages 392-403. SPE/IADC Drilling Conf (Amsterdam, the Netherlands, 2121-m), 2001. 

Direct hydration, of ethylene, 10 538 Direct hydrogenation, 6 827 Direct immunosensors, 14 154 Direct ingot (dingot) method, 25 409 Direct initiation, 14 270 Direct injection (DI) diesel engines, 12 421 Direct inlet injection, gas chromatography, 6 383, 415-416 Directional couplers, 17 446 Directional drilling techniques, in sulfur extraction, 23 572 Directive 89/107/EEC (EU), 12 36 Direct liquefaction, 6 827 Direct marketing, technical service personnel and, 24 343 Direct metal nitridation, 17 211-213 aerosol flow reactor, 17 211-212 Direct methanol fuel cells (DMFC),... 

Drilling Techniques for the Construction and Installation of Monitoring, Recovery, and Injection Wells... 

Drilling Technique Geologic Material3 Depth Limitations (ft) Well Typeb Remarks... 

Horizontal drilling techniques were originally developed in the petroleum industry. In the late 1980s, private industry and the federal government began development of horizontal drilling for environmental applications. 

Of course, it is lrequently desirable to utilize a controlled directional drilling technique. There are several reasons, as indicated by Fig. 15. The three most commonly patterned directional holes are shown in Fig. 16. The planned course of direction depends upon several factors, including rig capacity, hole size, mud program, types of formation, and the casing program. Meticulous surveying is required to achieve the desired results. Several types of drilling tools may be required. 

Although most U.S. Frasch mines were located inland, Freeport Sulfur Company pioneered offshore sulfur mining in the 1960s.15 The company utilized offshore oil drilling techniques to access several shallow water deposits. Developing a means to utilize saltwater to provide heated mine water presented the company with unique challenges in corrosion and scaling control. This now defunct facility, located in 200 ft of water 10 miles from the Mississipi Delta, commenced production in 1992 and closed in 2000. 

Align all the pieces to each other and c-clamp all four edges so that nothing moves while drilling the holes. Then, drill the holes. Drilling the holes in this manner assures that the screw holes will line up as they should. You can drill each piece separately, but be sure that your measurements and drilling technique are very accurate. 

When Edward Drake sank the first oil well as Titusville in 1859, nothing was known of prospecting methods or drilling techniques. A modest wooden structure supported a vertical ram, with an old motor and a series of iron pipes. Modern wells require a detailed study of the bedrock and can be drilled to over 20,000 feet under the most difficult conditions. 

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