Offshore gas temperaturepressure dynamic monitoring
The target project gas field is located in a self-block offshore platforms in the South China Sea. There are currently nine wells on the platform fully operational. In the early stage, monitoring underground gas reservoirs uses conventional electron temperature gauge. Seven has been installed, but failures appeared after a period (up to 1 year and a half) of working.
Meanwhile, the "monitoring and analysis technology with high water - reservoirs" special research project based on the "Twelve Five" sub-topic relates to the production of research studies sectional research and testing technology. It provide a breakthrough for invention / discovery more efficient development of deep, high-pressure, high-temperature reservoirs new technologies, and new processes.
The project selected permanent downhole fiber optic temperature and pressure monitoring system. Project requires the installation of a fiber optic temperature permanent pressure monitoring system, real-time monitoring of downhole pressure and temperature data (flow pressure / static pressure).
Well objective body structure diagram shown as below:
Project requires the installation of a permanent system of fiber-optic temperature and pressure sensors. Temperature permanent timely monitors wells within the wellbore during production, gas pressure parameter data and with the measured parameter data real-time transmission to the ground for display and storage.
Technical parameters requirements
Technical parameters Response
Monitoring point (temperature - pressure)
≥5 sec. 1 point
Pressure recovery:≥4 sec. 1 point
Normal work: Adjustable Frequency
Well string target structure shown as below:
②Introduction of system
The basic composition of the fiber permanent downhole pressure and temperature monitoring system as shown below. It can be divided into the underground part and the ground segment. Underground part mainly includes downhole temperature and pressure sensors, sensor holder tube, underground armored cable, cable protection; ground segment includes cable and terrestrial signal demodulator section.
Temperature and pressure sensor monitors the pressure in the tubing can be monitored when open wells flowing pressure, static pressure can be monitored shut.
The project was finished the underwell part by Sep. 2015. Project period is from Sep. 11, 2015 to Sep. 14, 2015
②Pictures of sites
Date & Time Temperature(°C) Pressure（Mpa）
2015-9-20 10:10:42 124.466556621448 27.1722753427491
2015-9-20 10:12:06 124.565240963854 27.1816863272276
2015-9-20 10:13:30 124.549052049044 27.1808111334052
2015-9-20 10:14:55 124.520704922409 27.1690734113194
2015-9-20 10:16:19 124.542984354256 27.1681846460941
2015-9-20 10:17:44 124.502479926057 27.1661434986337
2015-9-20 10:19:08 124.578049024851 27.15092922566
2015-9-20 10:20:32 124.487895501066 27.1376354809977
2015-9-20 10:21:55 124.497804053916 27.1330914706179
2015-9-20 10:23:19 124.470506253313 27.1452919631337
2015-9-20 10:24:43 124.545601082677 27.1694266835386
2015-9-20 10:26:08 124.460146218218 27.239049707156
2015-9-20 10:27:32 124.498570897468 27.2384125111733
2015-9-20 10:28:56 124.481971028241 27.2366385867947
2015-9-20 10:30:20 124.539460027077 27.2429867966579
①First use of Sapphire temperature and pressure sensor
The project is based on the world's first sapphire optical fiber temperature pressure sensor for the first time apply advanced offshore wells. The successful implementation of the project, marking the substantive breakthroughs in development and application of high temperature, high pressure fiber-permanent temperature and pressure sensing system. Fundamentally solved the problems of the world's ultra-high temperature, high pressure gas well downhole temperature and pressure dynamic monitoring.
②First use of gas wells
One well is implemented for the objectives well of the project. The successful implementation of the well, marking the successful application of sapphire-based fiber optic temperature and pressure sensors in the offshore platforms for oil and gas wells. It not only played an exemplary role in offshore platform dynamic monitoring, but also for land dynamic monitoring wells application.
③Deep high dynamic monitoring applications
The objective project well measured depth is 4051 meters, it is a high deep one. For these wells, there has been a difficulty to monitor the long-term dynamic monitoring. The successful implementation of the well for dynamic monitoring of land application of high or deep offshore platforms constitute iconic role model.