GW-Near Bit Geosteering Instrument
1. Brief Introduction
Near-bit measuring technology is a cutting-edge MWD and LWD technology, and also it’s the edge tool to precede high-end drilling technical service. This instrument is mainly applied in thin reservoir horizontal well drilling, oil (oil and water layer) boundary drilling, etc. It increases pay-zone drilling rate, single well production and recovery factor, and also it reduces development and production cost, achieve the efficient oil field development.
The characteristic of its short size (only 1m length) let it can be install behind the bit directly, and receive the real time geologic parameter and borehole trajectory parameters from the position less than one meter to downhole.
2. Technical Parameters
Tool OD
Max Operating Temp Max. Pressure
Continuous Operating Times Short Hop Transmission Distance Inclination
Inclination Measurement Accuracy
6?”
150°C 20000psi >150h >20m 0~180°
±0.5°@INC>30°
Measuring Range Measuring Accuracy Inclination Azimuth Angle Tool Face Inclination Azimuth Angle Tool Face 0~180° 0~360° 0~360° ±0.1° ±0.25° ±0.5° Directional Gamma module:
? Borehole imaging: 8 sectors, each 45° ? Measuring range: 0-380 API ? Measuring accuracy: 士3 API @ 50 API ? Max temperature: 150 ℃ ? Max pressure: 20,000 psi
Near bit Resistivity
Frequency 1Mhz
Range Accuracy
Amplitude 0.1-100Ω.m Phase
0.1-200Ω.m
Amplitude ±8% (0.1-25 ?.m); ±2 s/m(>25?.m)
Phase ±5% (0.1-30 Ω.m); ±0.6s/m(>30?.m)
Amplitude
Depth of Investigation
Phase
Vertical Resolution
32″ Rxo=1?.m, Rt=10?.m
55″ Rxo=10?.m, Rt=100?.m 20″ Rxo=1?.m, Rt=10?.m
34″ Rxo=10?.m, Rt=100?.m
Amplitude 12″ Phase
8″ GeoVision R6 Lateral Logging
0.35m
Gamma Imaging Near Bit Wired N 150℃
GW-NB
Electromagnetic Wave Logging 1m
Gamma Imaging Near Bit Wireless Y
150℃
3. Comparison with Similar Equipment
Instrument Name Method of measurement Max. Depth of investigation Borehole imaging Distance to downhole
Downhole data transmission Remote software update Working temperature
StarTrak Lateral Logging 0.35m
Electrical Imaging Near Bit Wired N 150℃
长城近钻头地质导向系统
1、应用领域
近钻头测量仪目前是国际随钻测量技术中的前沿技术，应用于薄油层水平井钻井、油层（油水层）边界钻井等，提高油层钻遇率，从而提高单井产量及采收率，降低开发与生产成本，实现油田的高效开发。近钻头测量仪与钻头连接，测点距钻头0.5米，可实时获得近钻头地质参数和轨迹参数。
2、系统主要技术指标及关键技术
相位电阻率：0.1-200 Ω.m 幅度电阻率：0.1-100 Ω.m
相位电阻率：±5% (0.1-30 Ω.m),±0.6 mS/m(>30 Ω.m) 幅度电阻率：±8% (0.1-25 Ω.m),±2 mS/m(>25 Ω.m)