The modern oil and gas industry provides various conditions in which the operator's ingenuity is of paramount importance. Challenges posed by remote reservoir locations and increased water depths result in elevated infrastructure, logistics and equipment costs. During the completion process production packers have traditionally been set using wireline or coiled tubing conveyed devices such as blanking plugs or check valves. The running and retrieving of these devices is time consuming requiring up to two intervention runs to run and retrieve. Wireline intervention also brings inherent risks to operations that can prove dangerous or costly to equipment and personel.
Reducing or removing intervention runs can significantly decrease rig time. The introduction of interventionless Packer setting devices has eliminated the need for wireline trips to set a packer and perform tubing tests to verify the integrity of the tubing string. Full bore type tubing isolation valve offers the ability to hold tubing pressure from above and below the closed flapper. This type of valve is run in the closed position as part of the packer tailpipe assembly. Run-in hole circulation can be achieved by a circulation valve above the isolation valve. The circulation valve can be cycled to the closed position providing full integrity of the tubing string. The isolation valve can then be cycled open after a determined number of pressure cycles that are used to set the packer and perform the required tubing tests.
The environment in which we now compete requires that we accept responsibility for protecting the environment surrounding our operations. It is important that we provide barriers preventing the premature flow of hydrocarbons to the environment.
Packer setting devices that enable us to hold pressure from above and below, can offer a dual role in their ability to suspend a well during and after the completion process. These devices can suspend wells for extended time periods. They can then be cycled open allowing full production flow. Well suspension enables the safe displacement of lighter fluids to provide an underbalanced situation with the benefit of providing a barrier that prevent flow from the underbalanced well.
One of the most important items required as part of the downhole jewelry on any type of well is the packer. The packer can be used for a number of different applications, be it production, Injection, isolation, or as a retainer for squeeze operations. Since the introduction of the first packers in the early 1900s, there have been numerous methods used for setting. The packer can be deployed on wireline, drillpipe, or on the production string, with activation achieved using traditional setting tools or the application of tubing pressure against a barrier device of some kind.
The prime focus in the early days was to get the packer in position and set successfully ensuring the packer was fully packed off against the casing ID. As technology advanced there was the need to increase the efficiency of the packer setting process. This need for efficiency was pushed even more as the need to drill deeper and further was required to reach the new pay zones.
Current deepwater operations average depths of approximately 20,000ft, increasing the time to complete these wells. Rig costs are averaging $800,000 to $1million per day so it is essential to improve the efficiency of operations. While the need for efficiency and cost savings is very important, this must not compromise the need for safety. Well control and efficiency are critical considerations when planning the drilling and completion of a well. This has presented a requirement for packer setting devices that hold pressure from above for packer initiation, and from below to provide a means of well control.