A team at Saudi Aramco’s EXPEC Advanced Research Center (EXPEC ARC), in collaboration with the University of Tulsa, recently achieved the first major field test milestone of its four-year project to develop the industry’s first downhole drilling microchip. The function test successfully proved the basic concept of the microchip system, a batch of 7 mm prototypes, which travelled about 6.6 km in the 8-3/8 inch wellbore to a depth of 3,368 meters (11,050 feet) and returned to the surface successfully.
Our dream was to develop a low-cost and alternative downhole data acquisition system capable of recording measurements such as pressure and temperature along the circulating path of drilling fluids. Such a technology would optimize mud and cement formulations while drilling and further reduce well cost by providing an alternative low cost data acquisition system.—Shaohua Zhou, DTT technologist
Currently, the primary function of the prototype microchip is to record in-situ mud temperature and pressure profile along the entire wellbore circulating path. Fiber optic mini sensors are used as part of the data recording system, while the internal design of the on-board chip is an open platform so that it can be adapted for many other mini sensors.
The device is pumped or dropped into the drill string and is capable of recording in-situ data which it stores on board while travelling downhole, eventually returning to surface with the circulating drilling fluid. Once recovered at the surface, the recorded data would be downloaded wirelessly for use at the rig site or transmitted back to an operation center.
Data retrieved from this test showed dynamic bottom-hole pressure of 7,500 psi and circulating bottom hole temperature of 190 °F (88 °C), consistent with static bottom hole pressure of 6,700 psi due to mud weight and wireline-tool-recorded static bottom hole temperature at 235 degrees. The field test also identified several areas for further improvements.
The next step will be to continue optimizing the microchips and further miniaturize the size while at the same time investigating the potential for various measurement sensors and optimizing the surface recovery method to achieve a commercially viable product in the near future.
We are very pleased with the field test results. This could be a game-changer, and we would even like to accelerate the deployment of microchips in our fields.—AbdulHameed Al-Rushaid, Drilling & Workover general manager
Successful development of the microchip potentially could change the way the industry acquires downhole data. Such data, which is rarely available in shallow and intermediate hole sections, can help drillers more readily diagnose hole problems while drilling to optimize and improve rig operations.
This is an important milestone in the development of this technology. Not only are we looking to improve the integrity of the drilling microchips but also to increase their capabilities beyond pressure and temperature.—Samer AlAshgar, manager of EXPEC ARC