This article describes the various issues to be considered for planning an offshore rig move. 1. Well/Jacket Status Well Plugging Prior to Rig Move If the current well path is less than 100 ft from any of the existing wells on the jacket, the wells shall be plugged with deep set plug and BPV. After … Offshore Rig Moves
In the event the casing string becomes stuck and all attempts to get it free are unsuccessful then , remedial action options shall differ according to the type of wellhead that is being employed and the depth of stuck point in relation with the different formation. The option to set the casing high can only … Stuck Casing – Remedial Action
If the maximum dogleg severity or maximum inclination is exceeded, the Drilling Supervisor must be consulted prior to taking any corrective action. An additional MMS should be taken while drilling, if doubt exists. Generally, at depths of +/-5 000 ft target size is sufficient to allow exclusive use of TOTCO inclinometer surveys because the radius … Survey Programme Example
The following definition of declination and grid convergence should be adhered to: Declination D is positive ‘+’ Grid Convergence G is positive ‘+’
Teledrift is an inclination-only mud pulse MWD system that can measure inclinations up to 10.5º. The system is available from Scientific Drilling International (SDI). The Teledrift is a purely mechanical system. The tool consists of a pendulum at the bottom that moves along a series of graduated stop shoulders, and a signalling plunger at the … Teledrift – Inclination-only MWD
Single-shot inclination-only survey tools are mechanical inclination indicators, often called by the trade name ‘TOTCO’ although they are also made by other manufacturers. They are normally owned and run by the drilling contractors. The instruments should be properly maintained and calibrated, at least every 25 shots. Operating Principle The TOTCO Drift Indicator is a simple … Single-shot inclination-only survey tools (TOTCO)
Successful performance in horizontal drilling of wells requires the development of a comprehensive database of experience as optimum practice is often very area specific. drilling parameters used, WOB, RPM, Torque, pressures, circulation rates etc. motor condition, stabiliser wear patterns mud properties comparison of predicted vs. actual BHA performance survey data, toolface control data hole conditions … Data Recording for Horizontal and ERD wells
The choice of bit should take into account the degree of re-active torque produced. For instance some PDC bits can make motor tool face control difficult resulting in erratic hole, increased torque and drag and low ROP’s. The use of motor bearing tri-cone bits is often preferred for these sections. Design Criteria for Selection of … Bit Selection and Hydraulics
Wells may require sidetracking in order to re-drill the well to a new target, sidetrack past a fish or sidetrack due to hole problems. The main requirements in sidetracking a well is the development of a lateral force to allow the bit to cut on the side of the hole. This lateral force should be … Sidetracking Guidelines
Deviated wells are normally drilled using a steerable system which is a combination of bent sub, motor and MWD allowing both rotary drilling and sliding without tripping for directional changes. Bottom Hole Assembly Generally the BHA shall comprise: tri-cone bit / PBC bits straight housing motor (low torque) bent sub non-magnetic drill collar drill collars … Steerable Systems