Distributed Temperature Sensing. On Demand. OPTICall Thermal Profile and Investigation Service
A New Line of Investigation for Improved Field Productivity Distributed temperature sensing (DTS) measures a wellbore s thermal profile and pinpoints production problems such as tubing leaks or underperforming gas-lift systems. The advantages of having these comprehensive capabilities are many operational flexibility, rig-time savings, improved data quality but until now DTS was not available for most of today s wells completed before this technology was an option. Still, other wells have not had access to this beneficial service because of economic constraints. Now Schlumberger brings you fast, cost-effective thermal profiling capabilities... on demand.
DTS on Demand Get the advantages of distributed temperature sensing through a line-conveyed service, when and where you need it. The OPTICall* thermal profile and investigation service delivers the only on-demand DTS available in the market. At your well quickly and deployed using slickline-type intervention, the OPTICall service uses the OpticLine* fiber-optic line for continuous, definitive data acquisition with minimal interference. Once the OpticLine system is deployed, you ll get the quick answers you need for improved productivity. Single-trip efficiency In addition to thermal profiling, the OpticLine system has the ability to run conventional production logging tools in memory mode. Save even more valuable rig time by using the OpticLine system as a method of logging sensor conveyance.
Immediate, Continuous Measurements The OPTICall service provides continuous measurements by thermally profiling the wellbore along the entire length of the fiber-optic line simultaneously. The result is a complete picture of downhole activity that enables a quick analysis of decreased production. The OPTICall service quickly and efficiently tracks fluid movements for real-time evaluation of performance and diagnosis of production issues. With this low-risk, highly economic monitoring solution, you can detect leaks, monitor gas lift valve performance, and evaluate fractures through an easily deployed service. Fiber-optic innovation The OpticLine system launches 10-nanosecond bursts of light down the optic fiber and backscatters a small amount. Rear-scattered light is then analyzed to measure temperature simultaneously along the entire length of the line. Answers at the Wellsite The immediacy of the OPTICall service results provides a distinctive advantage that saves time and money. As soon as the line is deployed, the data is instantly transported to the surface and can be analyzed on site. With no waiting for data analysis, many problems can be diagnosed quickly, and the best course of action for intervention can be followed. In addition to having immediate information for onsite diagnosis, you can request a more extensive field report for a more in-depth look at thermal events that indicate completion issues such as gas-lift malfunction or flow behind the casing. Definitive data analysis Using THERMA* thermal modeling and analysis software, you can further assess well flow performance. The software loads multiple DTS temperature traces for detailed data viewing in two or three dimensions. 53 42 Heel A B 1,200 1,400 1,600 1,800 2,000 Distance, m Reservoir interval Stimulated intervals No-flow zone Toe 00:32 00:02 01:32 01:02 02:22 02:02 Time
OPTICall Service at Work Prudhoe Bay case study: Fast identification of multiple tubing leaks The OPTICall service was used to quickly and accurately pinpoint multiple tubing leaks in a well in Prudhoe Bay. Initially, the well was completed without gas-lift capabilities, but when it was determined artificial lift would be required, the operator opted for the installation of gas-lift straddles. Two leaks were detected by using the OPTICall service, one near the upper gas-lift straddle and another at the lower tubing straddle. Instantaneous detection of temperature anomalies in the wellbore, as well as the quick deployment of the line-conveyed service, provided fast, cost-effective thermal profiling that allowed the operator to view ineffective completions and to improve field productivity.
Lake Maracaibo case study: Highly accurate detection of faulty gas lift The distributed temperature sensing technology of the OPTICall service was widely used in oil wells located at Lake Maracaibo, where approximately 95% of the wells are produced using gas lift. In one well, an OpticLine fiber-optic line was deployed to assess an entire gas-lift system and to determine if the well s instability was caused by low API gravity. During 12 hours of monitoring, thermal events were pinpointed at two valves located at different depths. A constant cooling effect at the first valve and intermittent activity at the deeper valve suggested inefficient gas lift. The highly accurate thermal profiling of wellbore activity allowed the operator to effectively plan a proper course of action for gas-lift optimization. Western Canada case study: Cost-effective multizone inflow monitoring An operator used the OPTICall service to successfully measure the temperature profile of multizone gas wells in the Deep Basin of Western Canada. A majority of the wells were completed using production tubing positioned near the lowest perforated interval to lift produced water to the surface. This form of completion made production logging more expensive because tubing had to be pulled before logging. Cost-effective distributed temperature sensing from the OPTICall service enabled inflow distribution to be calculated using a line-conveyed service without pulling the tubing. In addition to a reduction in operating costs, the on-demand DTS service ultimately led to increased efficiency in future reservoir stimulation practices.
OPTICall With the OPTICall service, you can track wellbore fluid movements, evaluate downhole performance, and diagnose production issues, all on demand. Thermally profile your entire well simultaneously, continuously, and in real time with fiber-optic technology that enables instant monitoring of dynamic temperature events. Get immediate answers at the wellsite, improve field productivity, and be certain. www.slb.com/welltesting *Mark of Schlumberger Other company, product, and service names are the properties of their respective owners. Copyright 2009 Schlumberger. All rights reserved. 09-TS-0277