ABC Wellsite Automation, Houston

The second annual American Business Conferences event hears from Emerson on operational performance. Noble reveal’s its ‘hidden (onshore safety) agenda.’ Devon manages by exception, wirelessly. Chevron advocates object-oriented scada. Murphy Oil automates rod pump management.

Predicting 2016 to be a ‘tough year’ Craig Llewellyn (Emerson) advocated investment in automation to address rising costs and to maximize ‘operational performance,’ a KPI that seeks to minimize downtime, lost production and costs. ‘Easy’ opportunities include tank management, custody transfer, enhancing separator performance, choke sizing and chemical use. Wireless scada offers an opportunity for a site-wide reduction in installation costs and enhanced process visibility. There are obstacles to automation, notably the inertia of a manual operations culture and a reluctance to invest in new kit. Llewellyn advocates starting with small projects to deliver quick wins, to retrain operators and also to ‘challenge your organization and automation partners’ to come up with ROI-generating scenarios.

Clint Boman (Noble Energy) has a ‘hidden agenda.’ Unconventional production and more stringent environmental considerations are making for increasingly complex production facilities. These need to cope with increased liquid volatility, higher gas volumes, operating pressures and new emissions controls. To ensure operational safety in the new normal, Boman takes inspiration from offshore safety systems, notably API RP 14C. While originally written for offshore facilities, RP 41C makes a ‘very good basis’ for onshore facilities as well. The standard can be used to drive a ‘prescriptive’ approach to safety instrumented systems (SIS) design and to take the guess work out of Hazop with a simple framework for deciding which safety devices are required for each process component. The intent is to develop a new prescriptive standard for onshore facilities where regulation or risk levels mandate full SIS implementation. Lower risk facilities can be covered with performance-based standards such as ISA84, IEC 61511, or IEC 61508.

Brandon Davis (Devon Energy) presented on the use of scada data in optimization. Davis acknowledged service providers Weatherford/Cygnet, Theta and OSIsoft and showed how these data services have been connected over a wireless network and into a central production control room. The infrastructure enables Devon to manage by exception and perform role-based analysis and decision making remotely. Operational parameters on RTUs and PLCs can be changed from the control room and key data feeds can be monitored at high frequency for troubleshooting end optimization. Set points can be adjusted automatically based on the results of accepted engineering calculations like Turner’s equation, Foss and Gaul and others. High frequency data logging and daily exception reports let operators see what is occurring without having to be on location or watching full time. Devon has built its own tools and dashboard for gas lift analysis, including components of Peloton’s WellView.

The production optimization dashboard was built with Theta Oilfield ServicesXSPOC/XDIAG and provides pump unit analytics and KPIs. Other tools offer support for liquid loading monitoring and ESP performance. Devon’s own brand ScadaNOW application rolls-up all of the above and adds an Esri map front end. The system captures some 150,000 values per day. Devon is currently working on an extension of ScadaNOW for its mobile workforce. Devon’s drillers likewise have their own tool, WellCON providing 24/7 data-driven decision support for geo-steering and fracking operations. Davis concluded that better communications and remote operations are key to Devon’s production effort and that the trend towards higher resolution data will continue and become more important across the board.

Chevron’s George Robertson has investigated the costs and benefits of object-oriented scada systems over conventional tag-based systems. The object approach allows meter behavior to be captured in a software object, and for objects to be assembled into larger component sub-systems that inherit constituent objects’ behaviors. There are downsides to the object approach, notably in development costs but these are generally outweighed by quicker and more robust deployment. In one case study, adding a new meter to the system took some 3 to 5 hours with a tag-based system but only 15 minutes using the object approach. This could easily amount to $700 per well per year in development cost savings. Robertson went on to discuss scada architecture and security to advocate segregating systems from the internet, from the business and even from neighboring scada systems. While it may seem attractive to deploy ‘one big system’ that is cheap and easy to maintain, that makes for one big single point of failure. On the other hand, hundreds of discrete systems make for a support nightmare. In between the two there has to be a sweet spot! Appropriate physical, logical and organizational barriers are needed to isolate segments and the enterprise should be able to survive the loss of a single segment. Segmentation is also important to avoid programming and configuration errors propagating too widely.

Fred Clarke showed how automating rod pumps is helping Murphy Oil maximize production, mitigate decline and cut costs. Murphy has 650 producers dispersed across the Eagle Ford shale area of Texas and some 500 beam pumps in operation. While automation has many benefits it is often misunderstood by management who may see it as a costly and complex addition that requires operator re-training. Clarke convinces management with plots of pump failure frequency against time that clearly show the benefits of installing controllers and variable speed devices (VSD) early in a well’s life. Automation can be carried out in stages. From ‘status only’ telemetry, through simple pump-off controllers to intelligent VSDs that offer added benefits of self optimization, remote operation and control of other equipment such as chemical pumps. Murphy’s high-end, intelligent VSD units offer lots more. From tubing, flowline and casing temperature and pressure, to leak and vibration detection and safety system monitoring. Automation also pays-off as non automated systems make for more site visit and slower decisions made from ‘dead’ data. Such considerations are especially important in shale wells whose rapid decline makes for changes in operating conditions. VSDs can adjust pump speed to keep pump fill near to the target range. Real time data provides a movie rather than a postcard allowing for optimization of every pump stroke.

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