Drilling in hot-hole applications results in additional time and care spent to ensure the integrity of temperature sensitive downhole tools. Rotary steerable systems, monitoring while drilling equipment, mud motors, drilling jars, and electronic sensor packages measuring vibration, loads, temperature, and pressure all have temperature limitations that, when met, require drilling ahead to halt so that the fluid system can be cooled down sufficiently enough to prevent damage to these tools. Conventional approaches such as circulating to cool and evaporative cooling systems are slow and costly. This paper will detail a solution that is capable of extending the running life of these temperature sensitive tools while reducing the overall cost of the well.
An innovative technology is now available to facilitate the rapid cooling of drilling fluids. The design departs from the nonproductive time spent simply circulating to cool and surpasses the economic capabilities of evaporative cooling systems. This closedloop system has been proven on multiple wells with a variety of configurations and operational parameters to confirm the nature of the system's performance abilities. Downhole tool life was monitored and reliability data gathered to show the improved functional life of these components relative to the performance of the fluid conditioning system.
Performance testing proved directly that run life of electronics can be increased by a factor as high as 43%. This extended run life resulted in reduced trips for changing out tools and in turn improved the overall drilling rate. The reduction in drilling fluid temperatures of up to 45 °F (at surface) and 21 °F at bottomhole in a single pass allowed a reduction in nonproductive time spent circulating to cool of more than a full day.
This paper focuses on the mud chiller performance data and for the overall operations on multiple wells drilled as part of a case study in hot-hole applications. Data presented in this paper will show that the system has the ability to shorten time to depth and reduce the overall cost of drilling operations.
