Down Hole Drilling for oil and gas exploration and extraction applications leverages many different types of electronic instruments. These systems are used for real time data logging of rock formations and position, and allow data acquisition in extremely harsh environments. There are several different types of logging tools, but they all have to withstand temperatures well above the traditional semiconductor recommended operating conditions.
- Wireline tools are dropped down a bore hole after it has been drilled and are powered by the wireline to log data for short periods of time.
- Logging While Drilling (LWD) and Measurement While Drilling (MWD) are typically battery operated measurements that are taken from sensors right above the drill bit on the drill string itself.
The use of many different types of sensors, require multiple channels of signal amplification and analog to digital conversion. MWD tools can measure position, pressure, temperature, vibration, shock, torque, and natural gamma rays. These systems can also provide information to microcontrollers (MCU) or Digital Signal Processors (DSP) to steer rotary steering tools for directional drilling. LWD tools measure different geological parameters like rock porosity, density, and resistivity. These typically require high resolution ADCs with greater than 16-bits to provide a detailed log of the geophysical properties of the formations.
The key consideration for tools in down hole use is operation at temperatures greater than 125C. Many of the current oil and gas wells have temperatures from 150C to 175C and the newest wells are approaching 200C and pressures of 20K psi. A thorough characterization at extended operating conditions is needed to provide information on how the parts will function at high temperatures. Leakage currents can become an issue at higher temperatures and many devices have thermal shutdown functions that need to be removed before a part can function at these extremes. Operating life data is also critical due to the reliability needs of these tools and the costs to pull and replace tools.
Since many tools are battery powered and with the already high ambient temperatures, selection of low power devices is important. By selecting the lowest power devices and limiting quiescent currents, longer tool and battery life can be achieved reducing costs. Along with low power, having the smallest packages possible also provides a way to integrate more and offer greater performance in the limited space available. Known Good Die (KGD) options are also desired by many manufactures that will build multi-chip modules or hybrids to save space.
A wide variety of TI products are available for down hole drilling systems and equipment manufacturers, including op amps, DSPs, microcontrollers, multi-channel high resolution data converters, interface, and power management.
Our High Reliability portfolio includes High Temperature product tailored to offer robust support in harsh environments.