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

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

All rotary BHA’s have a tendency to build and directional control is maintained by selecting a BHA which gives the desired build up rate (BUR). Due to the strong build tendency, it is preferable to err on the low side of vertical section as it is it will always be simpler to make a build … Guidelines for Rotary Directional Drilling

All mudmotors, non-magnetic drill collars, stabiliser mandrels and subs shall be inspected as per Company inspection programme. All tools supplied to the rig shall be accompanied by the appropriate documentation. All pin connections shall be stress-relieved and all boxes bored back. Bottom Hole Assembly In general, only the bit, drill collars, and stabilisers are taken … Directional BHA considerations

During the drilling operations phase the positional uncertainty must be monitored, especially when drilling in hole sections which exhibit collision risk. All borehole position calculations for well design, the survey database and well monitoring shall be performed with the Directional Drilling Contractor software. Anti-Collision Preferences Survey Tool Error System The system used in Company is … Positional Uncertainty

This article describes the surveying guidelines for wells with potential well control problems. Magnetic Single Shot / MWD In Exploration, Appraisal or Development well hole sections, where mobile hydrocarbons are present or potential well control problems could be encountered,  regularly spaced Magnetic Single Shot(MSS) (or MWD ) surveys shall be taken at a frequency not … Surveying Wells with Anticipated Well Control Problems

Tie-in data shall be provided by the Operations Engineer and sent to the rig for the Drilling Supervisor after completion of quality assurance check on each multi-shot MWD survey. The tie-in data will include: tie-in depth AHBDF (ft) inclination (degrees) azimuth (degrees) – referenced to UTM True Vertical Depth Below Derrick Floor (TVBDF) (ft) northing … Tie-In Data

This article describes the data to be includd in the various well plots. All plots, whether standard or non-standard shall include a: ‘Check/Signature’ box for the Operations Engineer and Petroleum Geology ‘Check/Signature’ box for the Senior Operations Engineer revision identifier indicated by a large character (A, B, C, etc.) supplemented by the date of the … Well Plots