This article describes the data required for a survey program and report.
1 General well data
·well name / ·wellhead co-ordinates (North, East, TVD, latitude and longitude) / ·co-ordinate reference (grid, true or magnetic North, type of grid system) / ·grid convergence and definition (in wording and drawing) / ·declination and definition (in wording and drawing) / ·depth reference / ·target direction / ·casing size and depths / ·pressures / ·temperatures / ·mud properties
2 Gyroscopic survey data
·tie-in point / ·time and date of programme / ·survey interval / ·survey frequency /·running speed (wireline operations) / ·spacing of TOTCO ring, baffle plate or UBHO sub for depth (single-shot / multi-shot / orienting / steering applications) / ·sensor spacing / ·tool type / ·probe number
·for conventional gyroscopic survey tools:
-angle unit type and range / -foresight reference used (position and angle) / -drift checks and drift rates (total observed and calculated) / -closure rate / -inrun/outrun inclination and azimuth difference / -wireline depth closure / -corrections applied (drift, tilt, inter-gimbal, foresight offset, toolface centre correction)
·for North seeking gyro tools:
-type of tool used / -operating mode: gyrocompassing or continuous mode / -pre- and post-calibration data /-quality control parameters / -if continuous mode, survey duration time and drift check data
·for Inertial Navigation:
-type of tool used including probe number / -pre- and post-calibration data
3 Magnetic survey data
The following is a list of tool specific data required for magnetic surveys
·tie-in point / ·time and date of survey programme /·Earth's magnetic field parameters (magnetic field strength, dip angle, declination) / ·declination definition (in wording and drawing) /·BHA description (inner and outer diameter of components, sensor spacing, NMDC length etc. ) / ·survey interval / ·survey frequency / ·spacing of TOTCO ring, baffle plate or UBHO sub for depth (single-shot / multi-shot / orienting / steering / MWD applications) /tool type / ·probe number
·for solid state magnetic survey tools:
-pre- and post-job calibration check data / -the raw accelerometer and magnetometer readings versus depth.
Other information
How the tool was run, e.g. wireline, wireline steering MWD etc:
·for wireline surveys
-wireline depth closure / -wireline depth correction applied / -toolface centre offset correction applied / -running gear, e.g. CCL, centralisers
·for wireline steering surveys
-BHA data including sensor spacing
·for MWD surveys
-BHA data including sensor spacing / -correction for BHA deflection applied