Levels of Smartness
From TheSmartField.com
Contents |
Introduction
There have been some discussions on how to classify wells as a function of smartness, degree of automation or awareness. The questions that immediately come to our mind are: How smart is a well?
- If we run downhole open/close valves, operated from a hydraulic pump from the surface, do that make my well smart?
- If we run a completion with downhole pressure and temperature sensors, do that make our well intelligent or smart? [1]
- If we run downhole interval control valves or chokes, operated from the surface, does this make my well intelligent?
- What is the difference between a conventional sliding door sleeve actuated from the surface with wireline and another well with downhole control valves operated from the surface with hydraulic lines?
Where does the intelligence reside?
- What are the Factors that define the intelligence in a Well?
- Can we categorize the wells where we deploy downhole instrumentation and controls and know what degree of intelligence they have or give us?
The intelligence of a smart well completion goes beyond the sophistication [1]
of control equipment deployed at subsurface and surface -it resides in the value that the added intelligence brings to the organization.
Let’s say your well has these capabilities: reservoir modeling, well modeling, data acquisition, data storage and surface facilities modeling. Will this be enough to label it as a smart well? If all these functionalities do not tie together and are not able to produce a two-way response, we are probably seeing a potential smart well moving in the early levels.
We can try with this approach, which we could call classification by level of smartness:
Level 1
- Well installations where downhole control devices are operated by cable, well pressure, hydraulic, pneumatic or hydraulic lines and need direct intervention to be operated. This is the case of sliding sleeve door devices, interval control valves with open/close characteristics and infinitely variable chokes. In all cases they need control assistance from the surface to operate the downhole devices, regardless if it is with a manual pump, a sophisticated Hydraulic/Pneumatic/Electric Power Unit or a wireline unit.
Level 2
- To this level will belong wells with mechanical, hydraulic, pneumatic or electric devices that operate automatically without direct intervention. These devices trigger an action over the well due to a programmed task. Examples of this level are wells with safety devices like a Subsurface Safety Valve (SSV) or Subsurface Surface Controlled Safety Valve (SSCSV), which act automatically when pressure or temperature limits are exceeded. The agents that control the shut-in process could be fully hydraulic or pneumatic, or their modern versions of Remote Terminal Units (RTU) and Programmable Logic Controllers (PLC) and electronic sensors. Another simple example could be a well with an automatic chemical injection pump; the pump will inject to the well at programed periods without human intervention. Wells with automated characteristics, that can modify their current status by monitoring locally and independently some well parameters, and acting upon them belong to this Level 2.
Level 3
We can group in this level the wells that enable people to perform some downhole or surface actions based on feedback at some point in the downstream process. The data acquired by downhole and surface sensors are gathered at a separation station - that could be located at the wellsite or tank battery or an Oil & Gas processing plant - is contrasted with real-time well production data and reservoir data, allowing the system to produce or recommend a response to change the well architecture or production pattern. In Level 3 we can be dealing with one well or a group of wells in a more ambitious scope field wide. This means that we should expect interaction between the final and measurable outcome from the well (oil, gas, water fluids), and the subsequent action to improve further the production or protect the asset of premature failure based on the feedback analyzed in the surface. The Level 3 system does not act independently – it needs human intervention to adjust and take action, but the most important thing is that the well loop intelligent system is giving recommendations to the production and reservoir groups that an action is required.
Level 4
It is Level 3 but the intelligent well system performs actions to correct production patterns by itself. They will self adjust taking actions which could include:
- Regulate downhole interval control valves to new positions
- Regulate surface adjustable choke valves
- Shut in or open zones
- Shut down the well
- Adjust intensity, rates, power of special subsurface devices
- Start maintenance routines in subsurface intelligent equipment: calibration, alignment, purge, etc.
- Produce actions on other facilities downstream in the chain like tank batteries or oil & gas processing plants.
- Change real-time acquisition frequency to production variables that need more attention
In Level 4 the key word is "interlinked processes" and "interlinked self-adjustment". A methodology to accomplish this would be a Model Predictive Control (MPC)[1] .
Level 5
In Level 5 the wells and the field are "aware" and become more independent of human action and reaction time is reduced to a minimum. New intelligent systems (cortex-function based) [1]
beyond of the computational tools available now (artificial intelligence, neural networks), along with nanotechnology tools are deployed in the wells and fields. In addition to self-adjustment, self-learning, self-adapting, [1]
automatic optimization,[1]
change of production patterns, interaction with other production system downstream, they can perform corrective activities on the formation. For instance, stimulation tasks will be performed by the same well awareness system. [1]
In contrast with a typical stimulation job, let's say in a fracturing job, the well awareness system would perform its own fractures using sophisticated equipment integrated to the well. The awareness system senses the changes and regulates how much stimulation it needs. The Level 5 system may carry micro-perforating charges to blast as needed; microseismic sensors, conventional downhole sensors and nano-sensors inserted into the formation will inform to the surface acquisition network what was the effect on the formation. Completion designs and well architecture will have to change dramatically to provide independence to the self-aware well.
References
