The Development of the First Expandable Sand Screen

Abstract

Abstract Eliminating the annulus between sand screens and the wellbore allows the well to be slimmed down by one casing size. This can result in dramatic well cost savings. Wells that require numerous casing strings to reach their objective, such as those in deep water environments, could benefit from such screens because they liberate an additional casing string for the same surface casing size. Once installed against the wellbore, an expandable screens would allow enhanced reservoir management activities. Zone isolation or treatment would be possible because of the elimination of the annulus. This paper describes the development of the first expandable sand screen from its concept to its successful application in producing wells. An expandable screen construction was developed using slotted tubes encased in filter strips. A filter media was chosen for the screen that offered the best balance between plugging resistance and sand retention efficiency. New manufacturing techniques were developed to produce the screen in commercially viable quantities and with the required quality. The screens were applied in both cased and openhole applications in offshore and land environments. The trials proved that the screens could be expanded to eliminate the annulus present in traditional sand control equipment applications. The system proved easy to install and reduces the likelihood of screen failure due to plugging and erosion. Introduction The decision to install sand control means in petroleum wells must take into account many varied factors; It is often difficult to predict from core analysis and production testing whether a particular field development will require sand control or sand management during its producing life. If the decision to install sand control equipment is taken, it can have a large impact on the design and operation of the well. There are numerous techniques for controlling sand production, but by far the most common techniques involve the installation of screens of varying design. Some disadvantages associated with the installation of sand control equipment in a well are:-–Higher equipment capital costs–Increased well installation time.–Reduced ability to modify or treat the reservoir inflow Profile.–Modification of the casing scheme to achieve the optimum screen internal flowing diameter. The authors believe that the major disadvantages of current screen related techniques are those associated with the presence of the annulus between the screen and the wellbore. The existence of the annulus results in a larger casing scheme design than ideally required and severely limits the ability to control the reservoir inflow profile. In some instances the screens are surrounded by a highly permeable gravel (gravel packs). Even with this technique, the permeability contrast between the gravel and the surrounding formation means that the gravel still acts as an empty annulus in terms of the ability to control the reservoir flow from within the screen.