positive tool orientation significantly improves data
TRANSCRIPT
Positive tool orientation significantly improves data quality and enables gravity descents of wireline tool-
strings to extreme deviations
Martin LeonardPetromac Technical Manager
Wireline Data Acquisition
Accurate and Efficient
Plagued by Mechanical Limitations• Ledging/Washouts/Cuttings• Deviation• Differential Sticking
✓
Wireline Logging Options
Logging Ledges Deviation Sticking Quality Sampling $ rig time
Wireline
Pipe Conveyed (PCL)
Tractor
Through Drillpipe
LWD
WL Conveyance System
Conveyance Sys & Tractor
Petromac
Centre of gravity
Rotational centre
logging
tool
• Orients the Guide upwards
• Aligns toolstring sensors on way in the hole, allowing data to be captured during down-log
• Prevents image rotational tracking
• Quicker / Improved fluid samples & pressures as taken from the high, undamaged, side of the wellbore
• Cores can be cut parallel to the bedding planes-valuable for core permeability measurement
Tool Taxi is stable sitting on it’s wheels, where centre of
gravity is lowest
Importance of Orientation
Alignment of Tool Sensors
• NMR data acquired in previous well in the same field was unusable• Orienting NMR with wheels yielded excellent data
SPE-192876-MS
SPE-192876-MS
Tool Centralization
• Traditional centralizing techniques result in high drag and stick-slip
• Centralizing using wheeled carriages results in low drag and excellent data quality
Formation Sampling - Permeability
Lowside vs Highside
• In deviated wells the weight of the drill pipe is borne on the low side of the wellbore:• Suspended cuttings are ground into the pore spaces• Drill pipe scours the sealing mud-cake from the wellbore wall,
thereby allowing repeated invasion of drilling fluids
• Sampling from the high side of the wellbore results in faster clean-up from improved permeability and less invasion
Formation Sampling – Sealing
• Probe packers are designed to match the curvature of the borehole and achieve the best seal when aligned perpendicular
• In deviated wells, tool will tend to ride on its side, which can create sealing problems
• Oriented sampling ensures excellent sealing
Oriented Coring
• In deviated wells, horizontal cores from the side of the wellbore are cut parallel to the bedding planes, rather than through them, which have more value for core analysis.
• Ability to core without any interference with the stress cage
Cores cut parallel to bedding planes.
Petromac
Tool 64 Deg
Taxi 77 Deg
Gen3 Taxi 82 Deg
Tool Drag
• 79° Deviation – ADNOC Offshore, UAE• 78° Deviation – B&W Energy, Gabon• 75° Deviation – Formation Sampling String – HESS, Malaysia
• Above these deviations, reduction in the Tool Drag, allows longer and deeper tractor operations
Conclusions
Current logging technology is Risk Mitigation
- Increase Power
Focus should be on Risk Prevention
- Positive Tool Orientation