This article describes the general handling and running guidelines for Measurement While Drilling (MWD) Handling Guidelines for Measurement While Drilling (MWD) tools Considerable care should be taken whenever handling MWD tools. They are built to withstand high axial loads but are easily damaged by transverse loading. MWD collars should always be snubbed when being … Measurement While Drilling (MWD) General Guidelines
The difference between the current Magnetic North for the location and Grid North is monitored for every survey by the Deviation Contractor and the Operations Engineer. All drilling plots and directional programmes shall contain the current approved value for correction. All surveys shall have azimuths pre-corrected to UTM.
Electronic Magnetic Multi-Shots (EMMS) are a definitive multi-shot surveying instruments. However, MWD data may be accepted as the definitive survey provided QA/QC results are within the acceptable criteria. They have the advantage of being relatively insensitive to compass spacing, less mechanical parts, more options for time setting and quality control outputs. Running Guidelines During Electronic … Electronic Magnetic Multi-Shots
The Magnetic Multi-Shot survey (MMS) differs from the Magnetic Single-Shot survey (MSS) in that the camera contains a continuous film roll, which is exposed and advanced at pre-set time intervals. The time interval is set such that at least two pictures are taken while the pipe is stationary in the slips, thus providing a complete … Magnetic Multi-Shots
The Magnetic Single Shot survey (MSS) is an accurate field-proven instrument measuring inclination and magnetic azimuth, which consists of an electronic timer, camera and combined compass / inclinometer. The instrument is run in the same way as the TOTCO. When the timer fires, a film disc is exposed to the angle unit, thus recording the … Magnetic Single Shots
Gyro Multi-Shots (GMS) shall only be run in preference to EMMS to verify the surveys used to drill a hole section where magnetic interference may not be corrected. Gyro Multi-Shots are also used for ‘tying-in’ MWD surveys. They are also used inside a driven conductor (where a Gyro Multi-Shots is required for tying-in shoe co-ordinates … Gyro Multi-Shots
The Gyro Single Shot is used for orienting purposes only. While drilling, Gyro Single Shot surveys shall be taken instead of magnetic surveys or MWD whenever magnetic interference may be present. Gyro Single Shot are also used for ‘tying-in’ MWD surveys. Interference is likely to happen within 50 ft of steel fish or casing strings … Gyro Single Shots
Gyro surveys will be taken when the casing has been run if it was not possible to perform an MMS in the open hole. There are two distinct groups of slim, surface reading, gyro surveying tools: those that require orientation to a foresight reference bearing on the surface (‘surface referenced’) and, those that seek True … Introduction to Gyro Surveys
This article describes the standards for Drillpipe and Bottom Hole Assembly (BHA). Pipe Tally Requirements Master Drillpipe Tally Book The master drill pipe tally book shall be kept by the Driller in the dog-house and in the Tool Pusher office. This is to be updated every tour. Both the drill pipe single and stand columns … Drillpipe and Bottom Hole Assembly – Standards
This article describes the various depth references used for drilling onshore and offshore wells: Reference Datum, Chart Datum (CD), Mean Sea Level (MSL), High Tide (HT), Low Tide (LT), Water Level (WL), Lowest Astronomical Tide (LAT), Depth Subsea (SS) Reference Datum For operations involving a rig, either onshore or offshore, all depths (either along hole … Depth Referencing