Technology Update: Moving Toward High-Flow-Rate Intelligent Wells
Authors: JPT staff _ 
Published: February 2015

New developments in analysis, modeling, and testing are playing a major role in advancing intelligent-completion technology toward the goal of withstanding sustained high flow rates. Completions that can deliver sustained high flow rates are crucial to helping operators meet the long-term challenges of developing reserves in subsea and deepwater environments.

High well costs, particularly in subsea and deepwater development projects, pose a continuous challenge to operators to "do more with less" to achieve the most efficient means of drilling and completing wells. The pressure is on to target more reservoirs and increase recoverables with fewer wells. Drilling-technology advances now enable well teams to reach deeper sands with more contact areas or reach multiple pockets in "designer" wellbores. To make these designer wellbores viable long-term producers, completion designs must be able to withstand sustained high production or injection rates for the wells' long life spans.

Intelligent-well technology, which allows for independent control of multiple reservoirs without the need for intervention, has contributed significantly to enhancing the functionality of designer wellbores in challenging environments. Increasingly, however, the question is, How can maximum functionality of an intelligent well be achieved in conjunction with high deliverability rates that are expected to be sustained for the next 10 to 20 years? With no industry data available, accurate modeling and validation testing are critical to advancing intelligent-well technology to its next logical application. Extensive efforts have been undertaken by Baker Oil Tools to predict accurately how high flow rates with the possibility of solids will affect the functionality and longevity of intelligent completions, with the primary focus being on the remotely operated valve.

Predicting Erosion

Erosion can affect the life of high-flow-rate completions significantly. Completion designs may include 10- to 20-year life expectancies with flow rates of 30,000 to 60,000 B/D. These rates are applicable for both production and injection wells. Tubing and casing sizes, pressure ratings, and flow areas are among criteria considered in all completion designs—with a goal of determining how much fluid can be produced from or injected into the well, as the case may be. In each instance, predictions of well deliverability must take into account subsequent velocity of the media that could include solids within the flow stream. How can these wells last 10 to 20 years at this constant rate?

There are many different models and methods available within the industry to predict erosion. The challenge is in applying these models to relatively new intelligent-well technologies. Studies use nodal analysis to predict deliverability, constraints, and pressure and velocity profiles of the individual wellbore. Computational-fluid-dynamics (CFD) software enables evaluation at the component level. How does one know that this CFD model is correct?

Nodal-analysis models used by the industry have proved to be reliable. The characteristics of suppliers' equipment are the unknown. How do specific design features affect flow rates into or from a wellbore? How do high flow rates with the possibility of solids affect the functionality and longevity of the completion?