Smart Well Technology
From Ontology to Application
Smart Well can be defined as a technology actually pertinent to complimentary equipment, monitoring the wellbore properties, collecting, transmitting or analyzing well and reservoir production data, then taking measures regarding segregating the well, sealing portions of the wellbore, and regulating the flow. These measures are carried out in a bid to enhance well production, and are triggered automatically or manually. A smart well is drilled vertically, horizontally or inclined. From initial well design concept to practice, smart approach to be taken regarding a well would be identified.
The profitability of Smart Well Technology and extent to which it enhances fluid production is
highly dependent on the inherent reservoir properties. From experience, reduction of the uncertainty in reservoir characterization, highly heterogeneous reservoirs with variable fluid delivery from each zone have proven to be suitable for the application of Smart Well Technology. The smart well technology can be applied for intelligent injection, intelligent gas lift, water or gas shut-off, commingled production, flow profiling, and dump flooding which are focused on:
For highly heterogeneous reservoirs, such as naturally fractured carbonates, the injection flow profile is rarely uniform. In such reservoir systems, the high permeability contrast between the natural fractures and the matrix cause most of the injected fluids to be captured through high permeability streaks, significantly leading to uneven injection profiles and poor sweep efficiency intelligent completion systems can regulate the injection rate along the well bore to create a more even injection profile.
2- Intelligent Gas Lift
Gas lift is adopted to increase oil production rates. Traditionally, gas compression facilities pump gas from the surface down the annulus of the well which then changes the flow properties of the oil downhole, reducing hydrostatic head and thus enabling higher flow rates to be achieved. This process requires substantial capital investment equipment such as pumps and compressors. In reservoir systems with a gas cap, intelligent completions can help eliminate the capital investment required for the surface facility in a traditional gas cap operation. In an intelligent gas lift operation, the gas-bearing zone can be completed and equipped with an intelligent well system. This allows the lift gas to be produced and bled into the production tubing at a controlled rate through the downhole flow valves. Intelligent gas lift is also commonly referred to as auto, in situ or natural gas lift. If executed well, intelligent gas lift generates additional value by completely eliminating the cost,
risks and platform load requirements associated with surface gas compression facilities, providing means of controlling gas coning, and eliminating the need for interventions to place traditional gas lift equipment.
3- Commingled Production
Commingled production is the flow of fluids, originating from two or more pools, in an unsegregated manner to a well measurement meter. Commingling is a method to maximize the total recoverable hydrocarbons from a well and it provides an opportunity to produce zones that may be individually
uneconomic to produce, either initially or after having declined to marginal rates. Commingling may also help to lift liquids to the surface that would otherwise hinder production. Using Smart Well Technology, commingled production can be achieved by choking the flow from high pressured zones to avoid cross flow to low pressured zones. This allows vertically stacked layers with different pressure profiles to be simultaneously produced, while adhering to regulation. Additional benefits are including accelerated production and elimination workovers requirements, both of which significantly add production value especially in deep water operations.
4- Water or Gas Shut-off
Produced water management is a real essential issue during the production of oil and gas. High water production rates can lead to the early end of life of a well due to the high cost of water treatment; however, considerable amount of oil is remained. Early water breakthrough can be detected through smart well technology by the temperature and pressure sensors in the downhole. Excessive water production can be controlled by completely shutting off or choking zones that breakthrough early. This can also be applied to control early gas influx into the well in situations where a gas cap is present while gas production is not desired.
5- Reduce the Uncertainty in Reservoir Characterization
Without proper reservoir characterization, it becomes challenging for engineers to properly manage the reservoir to obtain optimum production. Intelligent well completions provide real time downhole data which can be used to improve production models and reduce reservoir uncertainty. Intelligent completions provide data which enables more accurate reservoir characterization and optimizes future operations.
6- Dump Flooding
Dump flooding is a new technology that is adopted for water treatment. Based on this method, produced water is injected to a depleted reservoir. This method reduces the costs due to lack of surface facilities for water treatment. This technology is used in smart wells and can be considered for gas injection, too.
7- Flow Profiling
Collecting and understanding flow profile data of a well is essential for reservoir modeling. The methods to provide necessary data including well testing are almost not only expensive, but also time consuming and usually involve interrupting normal production. Some other methods that are simpler than well testing are risky and usually not accurate enough since they gather data by sending equipment downhole to the well. Smart completions are equipped with permanent downhole pressure sensors, thus the need for making trips or interrupting production is eliminated. Live pressure data can be constantly collected during production. Additionally, fiber optic technology which is integrated with smart well technology enables the operators collect temperature data, thus have a better understanding of the flow profile along the production tubing.