FLUID FLOW AND PARTICLE TRANSPORT ANALYSES SHOW MINIMAL EFFECT OF ANNULUS BETWEEN HORIZONTAL WELLBORE AND EXPANDABLE SCREEN

SimondsExpandable screens are increasing importance in sand control completions because of their capabilities to provide wellbore support and efficient cleanup after completion. This is particularly important for offshore horizontal wells. Currently, two types of screen expansion technologies exist; i.e., the constant diameter (fixed cone) expansion technology and the variable diameter expansion technology. Each has advantages and disadvantages for deployment, wellbore support, and inflow performance.

With fixed cone expansion, the industry has had the concern that annular flows between the openhole and screen can lead to transport of formation sands, localized screen erosion, and failure of the filtration layers. This paper discusses a method that can determine the probability of the above concerns with a model that analyzes extensive fluid flow and particle﷓transport. The forces acting on individual sand particles are modeled to ascertain the particle transport within the annulus and determine annular flow problems. This model can predict if there is any possibility that particles in the annulus will be transported. Using this method, the wellbore (annulus) section in which no particles could be transported can be predicted.

Computational fluid dynamic simulations were performed to study flow distribution in the horizontal wellbore. At a given wellbore location, the percentages of fluid flowing inside the basepipe and in the annulus were calculated. The simulations showed that average fluid velocity in the annulus is an order of magnitude less than the fluid velocity inside the base pipe. The study also showed that if designed properly, a screen with fixed cone expansion can be used successfully without concern of particle transport and with very limited flow in the annulus.

This paper provides insight into the movement of formation sand in the wellbore, including the annulus. Results from a field application will demonstrate the application of the model.