Fiber Optic Logging Technology
Optical fiber logging (also known as distributed optical fiber monitoring) technology. This technology uses the optical fiber itself as a sensor without instruments. By measuring backscattered light (similar to radar echo technology), it detects the temperature, Acoustic wave and strain data, so as to realize the monitoring of oil and gas well production, transformation process and transportation pipeline Optical fiber logging technology can provide complete and real-time reservoir production and injection dynamics without interfering with oilfield production. There is no need to produce logging instruments during operation. A single optical fiber can monitor well production in real time, greatly reducing It reduces the risks of downhole operations and saves operating costs for oil and gas fields. Optical fiber can be installed or sent into the well in a variety of ways. For oil and gas well life cycle monitoring, the optical cable can be fixed outside the tubing or casing and run into the well. For temporary monitoring, the optical cable can be sent into the well through auxiliary equipment such as coiled tubing, tractor, and steel wire. Go to the target layer for monitoring.
Fiber optic logging technology is one of the most advanced technologies in the logging industry in recent decades, overturning the traditional logging technology. In particular, it is effective in solving the problems of gas production, liquid injection, gas injection profile, fracturing reform process, liquid and proppant direction and inflow, and wellbore integrity in oil and gas fields.
1. Solve the problems of gas production, liquid production, gas injection and liquid injection profile in oil and gas fields. At present, in the production and development process of oil and gas fields, there are more and more horizontal wells, so the monitoring of the production profile of oil and gas horizontal wells becomes more and more important. Due to the high operational risks of traditional production logging, many wells cannot complete logging tasks. Optical fiber logging technology can monitor the production and supply rate of each perforation cluster downhole in real time, provide real downhole production conditions, provide prepared data for oil and gas fields to understand production rules, and provide decision-making basis for development plans.
2. Monitoring the integrity of wellbore without dead angles. Currently, major oil and gas fields have some old wells or difficult wells. The integrity of the wellbore is not clear, especially the problems of casing leakage/channeling and formation water/sand production are difficult to solve. Optical fiber logging technology is precisely the best way to solve this problem. This series of problems can be solved by running an optical fiber into the well.
3. Fracturing process monitoring For the current oil and gas industry, the topic we talk about the most is shale oil and gas\tight oil and gas, so the most commonly used method for developing this kind of oil and gas is hydraulic fracturing. But before, there is no technology that can directly monitor the transformation process. We don’t know where the liquid hit the well or where the proppant has entered, let alone which depth has entered, let alone how much? Fiber can be monitored. The direction and amount of fracturing fluid/proppant should be adjusted in time according to the monitoring results to make fracturing more targeted and achieve the effect of sweet fracturing.
4. Oil and gas pipeline monitoring reports the damage location in time to minimize the loss. For oil and gas pipelines, our conventional monitoring method is man-made inspections. This method is not only a waste of manpower, but is too inefficient. It is often known that the pipeline has been broken for a long time, which wastes costs and pollutes the environment. Now with the optical fiber monitoring technology, we can find the damaged point of the pipeline in time through the optical fiber, and issue an alarm, and then deal with it in time to minimize the cost and pollution.
5. Technical features and advantages
A. The optical fiber itself is a sensor, no instrument is needed, and the safety is high;
B. Static measurement method, the data is more real and credible, providing you with the most reliable basis for decision-making;
C. Supporting hardware equipment with the highest precision of optical fiber logging;
D. Experienced technical team, on-site real-time data interpretation, fine processing and interpretation in the later stage;
E. The unique optical fiber locator ensures that the permanent underground optical fiber is not damaged.
1) Ground equipment. The core equipment of ground equipment is laser transmitter and laser receiver.
2) Downhole tools. A single-core optical cable continuously detects and locates with a resolution of up to 1 meter, and a 10 kilometers long optical fiber is transformed into 10,000 sensors with a frequency range of <5 Hz to 20 kHz.
3) Data analysis software. The ground analysis box integrates a computer and self-developed acquisition and processing software
4) Distributed optical fiber temperature sensing equipment (ULTIMA DTS)
A. ULTIMA DTS system has the temperature and spatial resolution, and the temperature accuracy
up to 0.01 ℃, the spatial accuracy can reach 12.5 cm; it ensures that accurate data can be obtained in low-yield wells.
B. Suitable for single-ended and double-ended multimode fibers, the minimum measurement interval is 1 second.
5) Distributed optical fiber acoustic wave induction equipment—Carina
Carina system is a distributed optical fiber acoustic wave sensing product. While the product has fully upgraded the technology of the ground analysis box, the downhole optical fiber has been microstructured transformation. Greatly improve the intensity of the reflected light, so as to achieve the effect of improving data quality. The signal-to-noise ratio is improved by 100 times (20dB).
6) Interpretation method of distributed optical fiber layer profile
The heat capacities of oil, gas and water are different. When different fluids are produced in the reservoir, the Joule-Thomson effect can usually provide reliable information for the evaluation of produced fluid types.
7) The way of distributed optical fiber into the well
Based on different work content and requirements, the optical fiber can be deployed into the well through a variety of methods.
• Permanent installation: Installed outside the casing or tubing (full life cycle monitoring of oil and gas wells)
• Recyclable: coiled tubing, steel wire, pumping, crawler (short-term monitoring)
Shengli Oilfield Huitong Petroleum Engineering Co., Ltd.
Add: No. 466, Weifang Road, Dongying District, Dongying City, Shandong Province