Efficiency is a key factor on any operation. In this paper, we introduce the heterodyne Distributed Vibration Sensing (hDVS), which is an innovative technology based on fiber optic system to improve the duration of borehole seismic operations. We designed a survey aimed at comparing standard downhole geophone accelerometers measurements to i) optical fiber seismic installed inside the hybrid Wireline cable and ii) optical fiber clamped permanently to the well completion tubing. This comparison was conducted using a standard rig source VSP in association to advanced Offsets VSP. The purpose of the study was to evaluate this innovative technology and to assess the feasibility of drastic operation time reduction without compromising output data quality. To better evaluate the readiness of the technology, we decided to compare three distinct types of downhole measurements and designed a specific advanced acquisition which allowed us to compare various configurations. Consequently, the borehole seismic acquisition performed in the MR-SE1 well located in Makhrouga field (Tunisia) was split into two phases. Phase #1: during open-hole Wireline logging, using the standard downhole geophone accelerometers (VSI) and fiber optic seismic cable (single-mode cable) installed inside the Wireline logging cable (called hybrid Wireline cable). Phase #2: at the departure of the drilling rig, using a fiber optic seismic cable (single-mode cable) installed permanently along the intelligent completion. The results highlight the effectiveness of the hDVS technology with a proven decrease on operation timing, with reliable and good SNR recorded data. Nowadays, efficiency is a key requirement for any data acquisition process. The heterodyne Distributed Vibration Sensing (hDVS) is an innovative technology designed to achieve such effectiveness by making the Vertical Seismic Profile (VSP) a matter of minutes instead of hours, as using standard downhole equipment, without compromising output data reliability and allowing the measurements repeatability (no well interventions required). Finally, based on the quality of the dataset acquired, further analysis can be conducted for imaging purpose by analyzing the reflected waveforms, which could bring additional information and could change the way we are operating.

The Fully Retrievable ESP System Cable Deployed (CD) is a new technology which permits the rigless deployment of ultra slim OD Electrical Submersible Pump, able to reduce production loss while waiting for work over: these operations should be performed by a proprietary power and load carrying cable, and should be through tubing with the possibility to retrofit an existing completion. Based on previous Eni Partially Retrievable Experience, a R&D tender was launched among all ESP contractors interested to identify a complete rigless ESP solution. All technologies proposed were evaluated and Novomet was awarded the contract for the trial installation. Eni philosophy was to select the best candidate well which can be representative of the main criticalities of all Eni asset, in order to export the technology in the majority of operated fields. The scouting was performed among all Eni Geographical Business Units (GBU) and finally a well in Italy was selected to be the best candidate. The aim of the test was to install and operate the ESP for a short period of time, in order to validate the technology and diffuse it among the other GBU interested. It is important to highlight that the well selected is equipped with a Shallow Set Safety Valve, as common practices for ESP installation, so the R&D test will investigate also the functionality of the insert safety valve. The paper will describe all the steps needed to go further in a Rigless ESP installation project and all the lesson learnt that Eni can draw for the Oil & Gas Industry. The selected solution allows the retrofit option for the current shut-in wells, thus increasing the business opportunity for this type of technology. It is evident that each ESP solution (standard, partially or fully rigless) has pros & cons that will be discussed in the paper to guide the operator in the selection of the best possible option.

Objectives/Scope 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). Methods, Procedures, Process 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). Results, Observations, Conclusions 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. Novel/Additive Information 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).

The composite liner is made of a Glassfibre Reinforced Epoxy (GRE) resin, inserted in Carbon Steel tubing and it can be used in both production and water injection wells. Different laboratory tests performed either by manufacturers and by operators, have been carried out in order to confirm and verify the material characteristics and reliability. In particular, Eni in 2009 tested GRE in sour environment with CO2 and H2S to investigate the capability and service limits of the resin liner at different temperatures. According to the positive results of the tests, Eni has firstly applied GRE in 2005 in Tunisia where it was successful in reducing onshore workover costs and extending the life of Carbon Steel tubing in oil producer wells with high CO2 and water cut. The latest application was in Norway where it has been installed on water injector offshore wells, where, due to high corrosiveness of the injection fluid (raw seawater with antifouling chlorination), the liner was selected as cost effective alternative to high alloyed materials. More recently, Eni was involved in particularly challenging deepwater development projects with highly productive gas wells in sour and harsh environment. Typically, these applications require high grade Corrosion Resistant Alloys (CRA) production tubing with an important impact on the completion costs and operative run in hole issues. Following the positive experiences gained in the last 15 years in the application of glassfibre liner, it was evaluated the possibility to deploy the material as a corrosion barrier in well production tubings under more critical conditions. Eni decided to perform some additional laboratory tests in collaboration with Milan Polytechnic. Direct impact test and straight pipe test were performed in order to characterize the erosion behaviour of GRE composite material, supplied by two different manufacturers, and simulating the case of wells with high erosion rate risk. The results demonstrated GRE to have a good resistance to the solid particles erosion in comparison to very similar tests on Inconel Nickel Alloy material and confirmed the potential use of GRE as a corrosion resistance material when combined with Carbon Steel tubulars as an alternative to the usual high CRA materials in producer wells. This paper will present the characteristics of the technology, the laboratory tests performed with their results and the acceptable range of field conditions. Additionally, the paper will provide Eni field experiences, including feedback, lessons learned and economic evaluations.

Eni installed the world's first offshore Rigless Fully Retrievable Electrical Submersible Pump (RFR-ESP) system in an Eni Congo field in April 2012. The ESP failed after four years, and the system was successfully replaced rigless, by means of a slickline unit and a pumping unit. The job included the complete path from design and operations definition to the ESP commissioning and follow-up. Replacement operations were split in three different phases: Pull Out Of Hole (POOH): retrieval of the system and verification of the failed item(s).Run In Hole preparation: order, shipment, test and preparation of the items to be run in hole.Run In Hole (RIH): system deployment, commissioning and follow-up. The separation in time of the three phases was mainly due to the logistic arrangements required for the shipment of the various items to be replaced. Major attention was given to HSEQ aspects in every phase. The job resulted in the complete rigless replacement of the retrievable part of the ESP system, which allowed remarkable cost savings, compared to a rig intervention for the same scope of work, in terms of both direct costs and gains for avoiding well downtime and production delay. Better results and further contractions of times and costs could have been achieved by improving the management of operations and logistics. However, being this the first job of this kind worldwide, it was challenging in that no model or benchmark was available at that time. Some lessons learnt from the POOH phase were directly applied during the RIH phase, while others were reported in order to be implemented in future similar jobs. Since the economic impact of this type of job is remarkable, the sharing of knowledge is key to enhance performance of analogous applications, in a safe and efficient manner. This paper describes the job performed, explaining the choices made, the criticalities encountered, as well as the lessons learnt and the benefits achieved.