
Quick Downhole Shut In Tool Overview
posted on 16 January 2019 by James Wright
A downhole shut-in tool’s purpose is to enable the wellbore to be shut in downhole rather than at surface. The process of shutting in a well downhole eliminates the “wellbore storage effects”. Wellbore storage effects are the result of long lengths of production tubing that need to be pressurized before the buildup can be recorded. The benefit of using a downhole shut-in tool is to allow for a quicker well build-up and better pressure data quality. This saves operators money on downtime and gives reservoir engineers better data for their calculations.
- Patented Instant Close Valve (US#7823633)
- Multiple Cycles
- 10,000 psi differential pressure
- 150°C and 177°C Drive Options
- 2-3/8” to 2-7/8” Valve = 1.135 square inch flow
- 3-1/2” and larger = 2.50 square inch flow
Instant Close DataCan has a unique valve design that closes instantaneously giving the production engineer the best available pressure build up data.
Multi Cycle DataCan’s valve has the ability to re-open and close multiple times, this is necessary when reservoir engineers are performing three or four point isochronal pressure tests. DataCan’s production and injection valve designs are patented in the United States and Canada.
High Temperature Use Our motor and controls circuit has recently operated in a production 151°C gas condensate well. This well is the highest field temperature DataCan has seen and is a milestone for shut in tool operations. DataCan can confidently rate its drive section to 150°C. Further engineering is in progress to raise the operating temperature of the downhole shut in tool to 165°C and higher.
Shock resistance The DataCan instant close / multi-cycle downhole shut in tool is highly durable. Shut in tools are often mounted below locks or plugs. As such, it is necessary that our valve and drive section are capable of withstanding the most physical of downhole conditions.
Drawdown and build-up tests are often performed on production and injection wells at regular intervals to monitor the performance of the producing formations in the well. A typical test setup usually includes a downhole valve (shut in tool) which is placed in the well and manipulated by slick line.
There is usually a pressure recording device below the valve which records the pressure response of the formation being tested as the valve is opened or closed. The formation is allowed to flow for a sufficient length of time to ensure that it is drawn down to a desired level. After this draw down period is complete, the shut in valve is used to shut in the well. The formation pressure is allowed to build up for a sufficient period of time to allow it to reach a desired level, before another draw down period is started. The entire process is then sometimes repeated immediately to acquire more pressure data from another drawdown/build-up test.
There are two common sizes of valves, a 1.75” OD valve used for 2-3/8” and 2-7/8” tubing and a 2.5” OD valve for 3-1/2” and larger tubing. An important aspect of the downhole assembly, is the connection from the valve to the lock mandrel assembly.
The lock mandrel is set inside the lock, below the lock mandrel is a crossover, below the crossover is the DataCan valve, below the valve is a set of memory pressure gauges. The connection from the valve to the lock mandrel assembly is typically performed with a mechanical equalizing sub. There are two common types of mechanical equalizing subs, a sliding sleeve or a Kobe knockout type. DataCan recommends using the Kobe knockout type.
In any case, it is important to know the exact size and type of lock mandrel that is going to run downhole. The mechanical equalizing crossover is customized to attach to each specific type and size of lock mandrel. There are two common types of lock mandrels, the Otis type, and the Baker type. In each type, there are a variety of common sizes, each size is determined by the OD of the mechanical equalizing sub. Typical sizes are (in inches of diameter): 1.781, 1.875, 2.125, 2.188, 2.313, 2.56, 2.75, 2.813, 3.66, 3.81.
DataCan is able to manufacture a custom equalizing sub that wil integrate directly into the top of the valve housing. The DataCan mechanical equalizing solution means that your crossover solution will have at least one less potential leak path. DataCan highly recommends using an integrated mechanical equalizing sub to connect the downhole shut in tool to the lock mandrel.