Well logging
Mud logging
Mud logging service is aimed at information support of well construction process at oil and gas fields and includes:
- Process surveys;
- Geological and geochemical surveys and mud logging;
- Remote drilling monitoring.
Addressed objectives
Process surveys:
- Monitoring of drilling process parameters, including compliance with well drilling specification;
- Selection and maintenance of optimal drilling conditions;
- Optimization of round-trip operations;
- Forecasting and prevention of accidents;
- Fast detection of gas-, water-, and oil shows and losses during drilling;
- Monitoring of casing running.
Geological and geochemical surveys and mud logging:
- Sampling and fractional analysis of cuttings along well section;
- Evaluation of carbonate content and density of rocks;
- Luminescent analysis of cuttings and drilling mud;
- Continuous extraction of gases from drilling fluid flow at wellhead;
- Evaluation of volumetric and total gas content of drilling mud;
- Continuous rapid analysis of content of saturated hydrocarbons in gas mixtures extracted from the drilling liquid.
Remote drilling monitoring:
- Providing access to real-time and historical data of mud logging station (downhole telemetry system) from remote workstations;
- Possibility of setting up remote monitoring:
- Dispatch monitoring of well construction;
- Viewing and analyzing data received from monitoring objects;
- Analysis of technical and economic parameters (at well, field, company levels).
Mud logging is performed using Geotest-5 mud logging stations equipped with the Leuza drilling process monitoring system. Mud logging station is normally a chassis trailer based and includes:
Operator workstation (several computers connected to a LAN. Relevant office machines. Connection to computers of toolpusher and supervisor. Wire/wireless connection to workstations of drilling team, service companies, and supervisor. Hardware and software for data transmission from drilling rig);
Process module (for collecting, recording, visualization and monitoring of drilling parameters. It includes rig-mounted remote equipment), including:
- Drilling process parameters sensors (scope of sensors is determined by Client’s job specification)
- Weight on hook;
- Drawworks shaft rotations (depth sensor).
- Rotary table rotations;
- Rotary table torque;
- Discharge flow (discharge flow – indicator);
- Inlet flow (ultrasonic);
- Pump strokes (inlet flow – estimated);
- Inlet drilling fluid pressure;
- Drilling fluid level in receiving tank
- Inlet/outlet drilling fluid temperature;
- Drilling fluid weight;
- Tong torque;
- Discharge drilling fluid electric conductivity.
- Driller’s panel;
- Recording software.
Mud logging module (for recording, monitoring and study of gas content in drilling fluid) includes:
- Rubin chromatograph;
- Total gas content analyzer;
- Degasser with gas/air line;
- Gas sensors;
- Chrom software.
Geological module (for studying and recording cuttings, core and formation fluid data. It is equipped with exhaust hood and heated wash sink) including:
- Geological tools (scope is determined by Client’s job specification)
- Microprocessor carbonate meter;
- Cuttings density meter;
- Luminescent unit;
- Cuttings dryer;
- Microscope;
- Electronic balance, torsion balance, general laboratory balance;
- Fractional sieve;
- Chemical glassware, chemicals and consumables for cuttings analysis;
- GeoData software.
Rubin chromatograph
Function: Rapid analysis of saturated hydrocarbons content in gas mixtures;
Benefits:
- High sensitivity to hydrocarbon gases;
- Rapid analysis;
- Wide range of concentrations of analyzed gases.
Rubin chromatograph specifications
| Analyzed hydrocarbon components | СН4 — С6Н14 and higher |
| Detector type | FID |
| Propane sensitivity, % | No less than 1×10-5 |
| Upper limit of measured concentrations, % | 100 |
| Analysis cycle duration, s | Max. 120 |
| Carrier gas | Air |
| Carrier gas pressure, atm | 3.0 |
| Startup time, min | Max. 20 |
| Voltage/frequency, V/Hz | 150-280/40-60 |
| Power, kW | Max. 0.4 |
| Chromatograph weight, kg | 16 |
| Dimensions, mm | 446 х 218 х 264 |
Driller’s panel
Function: Collection from sensors, monitoring and visual display of main drilling process parameters. Display of alarms and messages for driller during drilling.
| Number of channels: — input analog signals: 22 — input discrete signals (TTL): 8 — output discrete signals (TTL): 8 — input/output signals (TTL): 5 |
| ADC resolution: 12 bits |
| Input signal level: 0 – 5 V; 0 – 10 V |
| Panel to computer communication channel: — RS-485 (optic isolated) — Radio channel (433 MHz) |
| Power voltage: 150-260 V |
| Ambient temperature: (- 45) — (+50) °С |
| Dimensions 600 х 400 х 120 mm |
Displayed parameters:
- Rotary table torque;
- Inlet drilling fluid pressure;
- Weight on bit;
- Weight on hook;
- Inlet drilling fluid weight;
- Drilling fluid level in receiving tank
- Inlet drilling fluid flow;
- Discharge drilling fluid flow;
- Bit off-bottom depth;
- Depth;
- Rate of penetration;
- Total gas content in drilling mud.
GeoData mud logging data processing software
Function:
- Processing, viewing and printing of mud logging data obtained during drilling:
- Generation and printing of mud logs.
GeoData software capabilities:
- Processing of raw mud logging data;
- Modeling of resulted well log;
- Visual and flexible data inputting and editing interface in mud log;
- User interface customization;
- Convenient preparation of document for printing;
- Compliance with mud log standards.
GeoData works with the following data:
- Rock lithology;
- Rock characteristic (density, porosity, carbonate content);
- Rock description (in text form);
- Age of deposits (in text form);
- Fluorescence analysis;
- Gas composition components and total gas;
- Process data: weight on hook, load etc.
Data format: Las-files, depth and time recording files