Reliable, sensitive downhole recorders obtain precise pressure data in a wide range of environments and allow highly accurate interpretations of that data.
CQG Crystal Quartz Gauge
Provides the most accurate, highest resolution pressure measurements available in the industry during downhole reservoir testing.
DataLatch System
System for data recording and readouts during drillstem testing.
UNIGAGE Pressure Gauge System
System for obtaining accurate pressure data in difficult downhole conditions.
CQG Crystal Quartz Gauge
The field-proven CQG crystal quartz gauge leads the market in high-quality pressure measurements. Designed from unique and proprietary sensor technology, the CQG gauge delivers consistently accurate results for improved reservoir characterization.
Most accurate measurements
The CQG design incorporates a single quartz crystal that measures pressure and temperature at the same point in the crystal. This unique feature dramatically reduces thermal effects and provides the most accurate pressure measurements available.
Highest resolution and accuracy
Small, residual thermal effects are further minimized with real-time dynamic compensation. This one-of-a-kind capability enables a fast pressure response for the highest resolution and accuracy under dynamic downhole conditions.
Minimal drift for ultimate stability
The CQG gauge’s unique dual-mode pressure sensor and highly accurate clock provides long-term pressure measurement with minimal drift for the ultimate stability. This stability and industry-leading resolution allows operators to see further into the reservoir and clearly detect boundaries.
DataLatch System
The DataLatch electrical wireline downhole recorder and transmitter system combines both downhole recording and surface readouts for well testing operations. It is built around a fullbore gauge carrier called the drillstem test gauge adaptor (DGA) and can support up to four UNIGAGE pressure gauges. Each gauge is powered and programmed individually and can be selectively ported to read the pressure above or below the test valve or in the annulus. In its simplest configuration-when only downhole recording is required-the DGA is run as a stand-alone gauge carrier, either above or below the packer. During surface readout operations, the DGA is run in conjunction with the LINC downhole electrical wireline connector. The data obtained by the DataLatch system are redundant, flexible, and high quality.
Typical job sequence
In a typical DataLatch system job, the gauges are programmed at the surface and the DataLatch system is run downhole with the drillstem test string. The gauges record the data as the well is being perforated, cleaned up, and drawn down. The well is then shut in and the LINC running tool (LRT) is run on wireline to retrieve the recorded data for analysis. A decision can then be made either to continue or to end the test. If the test continues, the gauges are reprogrammed for additional flow periods, and the LRT is pulled out of the hole.
UNIGAGE Pressure Gauge System
The Schlumberger UNIGAGE pressure gauge system provides high-quality, high-reliability pressure measurements during reservoir tests in exploration and development wells and during production tests on slicklines. The UNIGAGE system is built around either a high-resolution, high-stability quartz sensor (WCQR or WTQR) or a Schlumberger Sapphire pressure sensor (WTSR or SLSR). Both types of sensors provide high-quality data to ensure accurate interpretation of pressure measurements for optimum reservoir characterization.
The UNIGAGE system is designed for operations in harsh conditions such as H2S, CO2, acid, and TCP operations, and is compatible with highpressure, high-temperature jobs to 25,000 psi and 410 degF. Tests up to 1 year in duration can be performed.
A fast-recording rate recorder associated with a high-capacity memory allows the UNIGAGE system to fit with a broad range of test objectives and test durations. In addition, an intelligent memory management system, including memory guard, data reduction, and programmable windows, ensures full coverage of the well test even if more time is needed than was initially expected.
The WCQR sensor with quartz dual-mode oscillator and dynamic compensation provides outstanding metrological performance and is particularly well suited to high-permeability reservoirs with small pressure drawdowns.
The WTQR sensor equipped with a quartz sensor is an excellent choice in terms of accuracy, resolution, stability, reliability, and job duration requirements.
The UltraSapphire ultra high-pressure, high-temperature pressure gauge, WTSR, can be run by itself on monocable electric line for surface readout operations.
The SLSR is a cost-effective, efficient pressure gauge, particularly when run on slickline for downhole recording.
All UNIGAGE systems can be used in conjunction with the DataLatch system. This system has the benefit of a downhole valve to shut in the well, minimizing the ellbore storage effect and thereby shortening the test duration. The data are stored in memory but can be read at any time using a reliable inductive coupling method. An operational tool on an electric line allows full communication with the gauges, including data downloading, gauge reprogramming, and real-time surface readouts.
Benefits
- Provides high-quality data for optimum reservoir characterization
- Ensures reliable measurements in harsh environments and TCP operations
- Reduces test time