Data Transmission for High Temperature WellsTue, 01/22/2013 - 15:50
For decades, oil companies used the knowledge of geologists to try and understand the conditions surrounding the drill bit, but today, IOC’s are using a state-of-the-art technology known as measurement while drilling (MWD). This innovative technology gives drilling companies and engineers the ability to measure, the density, porosity, resistivity, acoustic-caliper, magnetic resonance, and formation pressure of a well while drilling, as well as the inclination of the drill bit. These measurements, which were usually acquired at different phases of the drilling process with logging while drilling (LWD) technology, have allowed drilling companies to drill more accurate, faster, and safer wells by delivering the real-time data at transmission rates quadruple the industry standard.
The main challenge for drilling companies is not the invention of measuring technologies, but rather creating devices with the ability to withstand immense pressures and extremely high temperatures. Over the last decade, the oil and gas industry has begun to focus on deepwater drilling, and with new oil discoveries in deepwater wells, oilfield service providers and drilling companies have created different instruments that can withstand these severe conditions. For example, Schlumberger has created two plastic board- mounted electronic components that are capable of withstanding high temperatures: a plastic-encapsulated and a ceramic-encapsulated electronic component. The plastic- encapsulated electronic component has a life expectancy of 1,000 hours at 150°C and 100 hours at 175°C, while the ceramic-encapsulated electronic component, which was designed for the US military, lasts longer at 175°C, but is larger and heavier; therefore, since space is limited in the drill bit, the ideal solution is to have a MWD encapsulated component made of a mixture of ceramic and plastic.
Schlumberger has made a large investment in the last eight years to develop electronic components that could potentially withstand high downhole temperatures of up to 200°C, but field testing is ongoing in order to meet the high expectations of customers in the deepwater drilling sector. Besides Schlumberger’s data transmission technology for high temperature wells, Baker Hughes also offers such solutions with its SMART Intervention technology. This innovative solution for data transmission, claims Baker Hughes, combines drilling optimization, real- time downhole measurements, and closed-loop process control, delivering a better understanding of what is happening at the business end of an intervention bottom- hole activity (BHA). Furthermore, this technology allows clients to make informed and on-time decisions that lead to the optimization of well intervention operations, not only reducing non-productive time (NPT), but also risk exposure.
Baker Hughes SMART Intervention service functions with a downhole data acquisition tool called SENTIO. The tool has sensors that acquire static measurements, digitalizes and analyzes the data acquired through the sensors, and then sends the data to a rig-floor display screen at the surface or to a remote real-time operations center. Despite being able to send information directly to the surface, the SENTIO tool has the ability to store and record data in the on-board memory, giving operators the ability to retrieve it at the surface for further evaluation.
Halliburton also offers data transmission for high temperature wells; however, their product, the Electromagnetic Telemetry Technology (EMT), works without fluids. Halliburton explains it created this product because “the downhole rocks are so brittle that their natural fractures alone cause significant fluid loss that could potentially affect mud pulse technology, and if telemetry signals disappear because of a fluid loss, the operator is suddenly working blind.” Therefore, Halliburton’s EMT MWD/LWD technology allows operators to have a two- way communication link between the surface and the tool downhole and by using low-frequency electromagnetic wave propagation, the EMT facilitates high-speed data transmission to and from the surface through any rock formation. Furthermore, the EMT provides a cost-effective alternative to pulse systems and makes drilling operations more cost-effective, which, according to Halliburton, “is another key differentiator from other data transmission services on the market.”
Baker Hughes, Schlumberger, and Halliburton’s data transmission solutions for high temperature wells allow operators to better understand well environment, offers them solutions for well intervention situations, and help optimize drilling operations and ultimately reduce risk while drilling. Their value proposition could be a good match with Pemex’s drilling ambitions. According to Carlos Morales Gil, Director General of Pemex Exploration and Production, his division will keep focusing on the niche of high-pressure, high-temperature wells, with the continuing help of service providers, while wells that require a different type of expertise will be handled by specialized drilling companies.