Slim hole Wells - Overview

Wells can now be safely and effectively drilled or sidetracked, evaluated and completed in small diameters down to 4 1/8". The resulting slim wells can provide a total well cost reduction of 30%. At…

Completion technology for Slim hole wells

Wells drilled using slim hole techniques are reducing initial drilling costs. The technology to conduct effective petrophysical evaluation in slim wells is available. Thus, slim hole development wells…

Wellheads, Xmas trees and BOPs for Slim Hole Wells

Slimming down wells can have a substantial impact on the cost and size of wellheads, Xmas trees, and BOP stacks. As a rough guide the weight, size, and hence costs of these components is proportional…

Continuous coring method - Slim Hole Wells

The continuous coring method is the utilisation of modified small mining (or other) rigs capable of continuous coring using wireline retrievable core barrels, coupled with on-site evaluation of the…

Slim hole Drilling Techniques

Five different slim hole drilling approaches are discussed in this article. In continuous coring there was a strong drive to maximise the amount of geological information, while the shallow rotary and…

Production testing - Slim Hole Wells

One of the applications of slim hole drilling technology is for low cost exploration and delineation wells. Slim wells from fixed rigs (land/jackup/swamp) can be drilled using the down-sized…

Drill string design (slim hole wells)

Over the years a standard set of API sizes have evolved to reflect the materials and manufacturing technology, operating practices, and stress analysis techniques. Drillstring design for slim hole…

Slim hole well wireline logging

Schlumberger has a set of 2 3/4" diameter tools offering all services for 4 1/8" holes. These tools have ratings of 175°C (350°F) and 137 MPa (20 kpsi) or better. The efforts to reduce micro-scanners…

Well control for slim hole wells

Well control for slim hole wells can be split into two areas for both continuous coring and downsized conventional drilling: Kick detection/ shut-in procedures and Well killing.

1 Kick detection and…

Environmental impact of Slim Hole Drilling

Downsizing wells has environmental benefits. During drilling the volume of cuttings, waste mud and cement are reduced roughly in proportion to the square of the hole diameter at total depth. Once slim…

Vibration minimisation for conventional Slim Hole Drilling

Minimizing Vibration - Specialy for slim hole drilling with downsized conventional or retrofit equipment, the larger relative annular clearances required to facilitate kick detection and control, low…

Muds, hydraulics and lost circulation for Slim Hole Drilling - Continuous coring

Muds are a critical part of an optimised slim hole drilling system. The design of the mud for all slim wells must be closely integrated with the hydraulics program, which is in turn closely integrated…

Muds, hydraulics and lost circulation for Slim Hole Drilling - downsized conventional drilling

Muds are a critical part of an optimised slim hole drilling system. The design of the mud for all slim wells must be closely integrated with the hydraulics program, which is in turn closely integrated…

Historical problems with slim hole drilling

In the past small holes could not be drilled safely and effectively. The article describes the main historical problems encountered when trying to introduce slim wells:

The tri-cone rock bit, rotated…

Coring in Slim Hole Wells

When drilling downsized conventional holes, conventional core barrels can be used. The addition of the anti-vibration technology (soft torque, thruster, Moineau motor, etc.) will improve penetration…

List of companies - Slim Hole Wells services

Please contact us if you would like to be added to the following list of suppliers:

  • Coiled tubing completions: Camco, Nowcam, Otis
  • Surface torsional vibration control: Bentec, Maritime Hydraulics,…

Downsized conventional drilling - Slim Hole Wells

Downsized conventional drilling is the use of a fit-for-purpose rig to drill conventionally a well with a reduced casing scheme ending in 4 3/4" or smaller open hole, possibly with a 3 1/2" production…

Evaluation of slim hole wells

All regular evaluation techniques such as wireline logging, MWD logging, mud logging, etc. may be used in slim wells. In addition on-site core evaluation is available commercially for continuously…

Casing, liners and cementing for Slim Hole Wells

As a well is downsized the collapse and internal pressure ratings of the surface and intermediate casing and liner string increase. Thus liners can be used further up the hole than with conventional…

Vibration minimisation for continuous coring in Slim Hole Drilling

For Continuous Coring Slim Hole Drilling the basic geometry of the drilling system required to facilitate wireline retrieval of cores through the drillpipe provides much of the vibration minimisation.…

Surveying Slim Hole Wells

A number of small MWDs and steering tools are available, mainly intended for the horizontal sidetrack market. There are a number of small gyros which were designed to be run through conventional…

Rigs for Slim Hole Drilling

Most slim wells are drilled and completed with a down-sized conventional approach using completely conventional drilling rigs, or modified workover hoists, as this is the cheapest solution. The…