This paper summarizes the innovative peculiarities and the result of field trial installation on ENI well in South Italy of the new Insert Sucker Rod Surface Controlled Subsurface Safety Valve ISRSCSSV.
The ISRSCSSV, combined to a modified lock mandrel, is sucker rod retrievable and is possible to install in a WRSCSSV landing nipple. It is a normally closed failsafe safety valve so the CL pressure keeps the valve open (Orsini 2018).
The innovation resides in a variable geometry sealing mechanism, able to shut in the annular area between the sucker rod and the valve external body. The sealing path is composed of a segmented tapered pads system located at the end of the elastic fingers, travelling along a cone housing. The ISRSCSSV combined with the Hybrid Pump determines a new approach for interventions on existing wells completed for spontaneous flowing without workover, representing a first fundamental step towards the application of the dual barrier policy in production wells. The Innovation allows safely operating wells and recovering oil otherwise not economically advantageous (Mennilli 2019).
The ISRSCSSV applies when need to convert a spontaneous flowing o ESP wells to the sucker rod artificial lift.
After the manufacturing of the ISRSCSSV, the related modified lock mandrel prototypes and the dedicated test fixture, the functional test performed as per API 14A (2015)/UNI EN ISO 10432 annex C (2004), was successful. Before the installation in ENI's well, a shallow test well equipped with all the necessary accessories to install and test the Hybrid Pump, and the downhole safety valve was completed, the test results were positive. On January 2020 ENI after attending the above tests, decided to run a field trial installation, function test, and retrieving in a well located in South Italy. On the field, after the ISRSCSSV installation, the safety valve lock mandrel was tested to verify the hold-down mechanism. The ISRSCSSV test was performed applying pressure inside the tubing against a wireline plug. Then closed the ISRSCSSV, bled off 50% of the wellhead pressure and performed a positive test as per API 14A (2015). The field test ended with the assembly retrieving applying the necessary over pull to release the lock mandrel retainer system. The overall result of the trial was considered positive.
ISRSCSSV represents the first safety valve existing in the body of literature for wells with sucker rod artificial lift system, allowing the compliance to the dual barrier policy. Moreover, this approach gives the possibility to install and retrieve the safety valve always with the rods string, with considerable time and subsequent cost saving, safeguarding the protection of the environment and the Oil Company image (Mennilli 2019).