Circulation valves are used in drilling and completion applications in a variety of configurations. They are used in the tool string to boost annular velocity, remove debris from the wellbore, perform well integrity tests, enable fluid movement between tubing and casing, and prevent pulling a wet string. In many applications, multiple cycles (open and close) are required to in order to complete multiple tasks in one trip. Multiple cycles can be achieved using mechanically activated circulation valves. However, in some configurations mechanically activated circulation valves require a hard bottom to manipulate the tool string. Consequently, a hydraulically activated multi-cycle circulation valve is desired in many applications, especially in deep wells, deviated wells, and drilling applications.
An innovative ball-activated multi-cycle circulation valve (BAMCCV) has been developed for these applications. The circulation valve provides three flow modes: to the bit only, to the circulation ports only, or a split flow between the bit and circulation ports. Three different size activation balls are used to manipulate the BAMCCV to these flow modes. In cased hole displacement, openhole drilling, and wellbore cleanup applications, flow can be split to maximize annular velocity for improved debris transport. In openhole drilling applications the BAMCCV can also be used in the circulation ports-only mode when lost circulation material must be spotted. This prevents spotted fluids from entering sensitive and expensive equipment such as measurement-while-drilling (MWD) and logging-while-drilling (LWD) tools. Blocking flow to the bit may also be desirable to maximize flow through the circulation ports when flushing debris out of recesses in blowout preventers. The decision whether to allow flow or to not allow flow to the bit when the circulation ports are open can be implemented at any time. The circulation ports can be opened and closed in the BAMCCV up to seven times. This enables greater efficiency in downhole operation by enabling multiple functions in a single trip. This paper presents the design, engineering, testing, field trial results, application and function of this new circulation valve.
The innovative BAMCCV can be used in a wide range of applications, and can be manipulated between three flow modes by dropping the correctly size ball. It enables performing multiple operations in one trip, and provides flexibility in selecting flow modes in response to well conditions. This flexibility is particularly important in deep, deviated, and problematic wells.