Safe and Economic Attractive Rigless Operations Using a Digital Slickline in Unmanned Platform with Low Structure Loads and Spacing
Authors: Mahmoud Radwan M. F. 
Published: November 2020

The general issue in oil and gas fields is maximizing the utilize of rig-less operations to solve all problems of wells, increasing the production rate, downhole logging and measurement e.g.: water shut-off, well integrity, thru-tubing perforation, wireline plugs, production logging for cost reduction especially with the oil prices at the time being.

Slickline operations in oil and gas wells have been performed for 90 years. Electric line (E-line) and a conventional slickline are important and frequently used tools for light well intervention operations, and are often used at different times during the same well intervention program, leading to multiple rig-ups and rig-downs of the equipment, as well as the requirement to transport both units to the platform (Jongnarungsin, S. et al. 2017).

In recent years a digital slickline technology has been developed and performing a wider range of well interventions with greater scope, certainty, and control (Billingham, M. et al. 2011/2012).

The digital slickline technology combines the capabilities of an Electric line and conventional slickline.

Digital Slickline's light, minimal foot print and modular make up coupled with its digital telemetry enablement allows operators to access wells and perform conventional slickline operations, plus perforating, plug setting and production logging, all with downhole in-situ information available on surface in real time, bringing huge operational efficiencies as well as reducing considerably the risks and uncertainties of the intervention programs being undertaken (Abdul Razak, M. et al. 2014).

This paper discusses how the rig-less perforation operation using a digital slickline as proved to be an economic attractive and safe solution in offshore unmanned platform with low structure loads and spacing in a dual completion well.

The case study well was completed as a dual producer in Apr-2015 via unmanned platform with restricted loads and space in Gulf of Suez-Egypt; long string produce oil & short string produce gas. Long string well production performance showed gradual decline till ceased to flow. To enhance the well productivity; it is recommended to add 67 ft in R-1 reservoir using a digital slickline.

The job challenges

■ Low structure loads and spacing of unmanned platform. ■ Rough weather condition in the area. ■ The new intervals of R-1 reservoir with about 1270 psia pressure greater than the R-2 perforation. ■ Limited time of a daily activity.

The intervention operation was completed as planned using a digital slickline perforation services, a single unit with small footprint low weight and single crew performed the perforation operations.

The intervention operation took approximately 4 days after that the long string well was initially produced 650 Bbl/d condensate & 10 MMSCf/d. Total cost as a result of time saved was US$ 51,000 below the original authorization of expenditure by reducing the time required to mobilize and move electric line and slickline units on and off around the helideck and by reducing the standby costs in addition to eliminate the potential risks of the movement of personnel and equipment.

Cost saving as a function of time can quickly multiply depending on water depth capabilities, deck space and weather conditions.

Based on results obtained from the case study well, the intervention operation using a digital slickline with good planning and preparation has proved to be an economic attractive and safe solution in offshore unmanned platform with low structure loads and spacing.