New generation expandable sand screens

Abstract

This thesis aims to give a general insight into sand control and various sorts of sand control measures and applications of sand control tools. Special focus will be given to expandable sand screens – a technology which came about in the late 1990’s through the use of flexible, expandable tubulars as base pipe in sand screens. More specifically Darcy’s Hydraulic Endurance Screens, a compliant sand screen system using hydraulic activation, and the future use of these will be discussed. This technology has been successfully deployed in a test rig environment(System Integration Test)14 and was planned to be field tested for Statoil on the Statfjord field(Well B-03)14, an operation which eventually was delayed as the 9 5/8“ casing above the reservoir could not be cemented due to heavy losses. Insight will be given into possible future use of the Hydraulic Endurance screens - specifically in water injector wells. Sand control is one of the key aspects to be considered when planning the completion of a well. Sand control tools may not always be necessary in a well - at least not from the start – and whether or not these are to be installed is one of the first things that need to be decided on. However, in poorly consolidated or unconsolidated sandstone reservoirs sand production is one of the biggest challenges for the completion and production engineers and some sort of sand control tools will almost always have to be installed at some point during the wells lifecycle. These tools or sand control methods may include, but are not limited to, slotted or pre-drilled liners, gravel packs, frac packs, selective perforations, oriented perforations or as mentioned above, different types of sand screens. All of these sand control measures and their use will be discussed. In water injectors, sand production poses certain specific challenges. These challenges usually arise not during the actual water injection, but when for various reasons the injection has to be stopped and the well is shut-in. These “water injector”-specific challenges include reservoir cross-flow between formation layers of different permeability, the “water hammer” phenomenon, well-to-well backflow, thermal fractures and gravel loss into fracture systems. If one or more of these factors come into play, sand production may be initiated and a situation where the injection well is filled with sand may be the case. It is the aim of this thesis to discuss and analyze whether or not the Darcy’s Hydraulic Endurance Screens may solve or improve on these challenges in water injectors and how they compare to the Open Hole Gravel Pack and the Stand Alone Screen, specifically with a possible use at the Johan Sverdrup field in mind. A theoretical case of a field installation of Darcy’s Hydraulic Endurance Screens in a water injector well at the Johan Sverdrup field will be presented. It was found that Darcy’s Hydraulic Endurance Screen is a fully viable alternative to Open Hole Gravel Packs and Stand Alone Screens in water injector wells. It is particularly well suited for the Johan Sverdrup field as the innovative utilization of a solid base pipe together with a compliant screen design enables among other things injection selectivity with the possibility of future shut-off, integration of Inflow Control Devices and easier filter cake removal - factors that may be vital in the two-zone reservoir encountered at the Johan Sverdrup field. Uncertainties with the Hydraulic Endurance screens mostly relate to the lack of experience running the system.