Wellpath planning and anti-collision monitoring - COMPASS

The Drilling Engineer must ensure that the wellhead co-ordinates and the target co-ordinates are given in the same co-ordinate system (origin, azimuth depth reference).

When storing the well proposal,…

Magnetic Single 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 /…

Non-Magnetic Drill Collars

Requirements relating to NMDC use when surveying with magnetic instruments..

NMDC Length

Every magnetic compass placed in a steel BHA will exhibit an azimuth error. This is caused by the interference…

Magnetic surveying techniques

Magnetic surveying techniques

The azimuth of the borehole is determined from the Earth's magnetic field using a magnetic survey tool.

Two basic types of tools exist, i.e. conventional photo-mechanical and solid state tools. For…

Solid state magnetic survey tools

Solid state magnetic survey tools

The tools measure Earth's gravity and magnetic field with solid state accelerometers and magnetometers (raw sensor data), respectively. Survey tools can be used as single and multi-shot tools dropped…

Conventional magnetic single-shot survey tools: Pre-survey checklist and Running procedures

Conventional magnetic single-shot survey tools: Pre-survey checklist and Running procedures

Pre-survey checklist & Running procedures for conventional magnetic single-shot survey tools:

Magnetic single-shot survey tools - Pre-survey checklist

MSS tools are normally run by the Driller.…

Conventional magnetic survey tools

Conventional magnetic survey tools consist of a mechanical inclinometer, i.e. a pendulum and a compass to determine azimuth. They are used as magnetic single-shot (MSS) and magnetic multi-shot (MMS).…

Correction programmes for magnetic survey

The correction programme corrects the inclination and azimuth values for cross-axial and axial magnetic interference of the drillstring (including magnetic hot-spots in NMDCs), bias uncertainties of…

Electronic Magnetic Multi-Shots

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…

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…

Running procedures for solid state magnetic multi-shot directional survey tools

Running procedures for solid state magnetic multi-shot directional survey tools.

  1. Check that the battery voltage and amperage conform to specification.
  2. Load the battery pack.
  3. Connect the directional…

Correction for Magnetic Azimuths

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…

Introduction to Magnetic Surveys

When running a magnetic surveying instrument, the following guidelines shoud be adhered to:

  • to eliminate external magnetic interference, surveys shall not be taken within 30 ft of a casing shoe
  • all…

Conventional multi-shots magnetic survey tools: Pre-survey checklist & Running procedure

This article presents a pre-survey checklist & running procedure for conventional multi-shots magnetic survey tools:

Pre-survey Checklist

MMSs are normally run by a Survey Engineer. The…