Executive Summary                                                                                                                             Ian Collins, BP Exploration

Welcome to the final 2015 edition of SPE Production & Operations. I enjoyed selecting the papers for this issue because it allowed me to continue my education in wells technology. I would highly recommend the Executive Editor role to those of you who want to broaden your education in petroleum technology! I have now been in the role for a year, and I am still amazed by the diversity of the papers we receive. In addition to the technical diversity, we see increasing geographical diversity from our authors, which benefits us all in exposing us to different ideas and concepts. Finally, I would like to thank all of the authors who have submitted papers this year. I realize that not all of you are successful in having your paper accepted. However, please be encouraged by the fact that our acceptance rate is increasing, driven by an improvement in the quality of the papers that we receive. Keep it up!

We have two quite distinct themes in this issue—Wells and Production Technology and Environmental Concerns in Treating Wells. The first paper in this issue is A Probabilistic Methodology To Evaluate the Cost Efficiency of Rigless Technology for Subsea Multiwell Abandonment. In a few years, there will be a need to perform a number of subsea plug-and-abandonment operations in the Norwegian sector of the North. This paper describes a probabilistic approach to assessing the cost- and duration-saving potential of using rigless technologies for this purpose.

We follow this with a paper that evaluates typical SAGD completions used in Alberta, Canada, for use with passive outflow-control devices (Design and Field Evaluation of Tubing-Deployed Passive Outflow-Control Devices in Steam-Assisted-Gravity-Drainage Injection Wells). Then, we move onto an excellent paper that discusses methods for production forecasting in unconventional reservoirs that allows horizontal well completions to be optimized (Economic Optimization of Horizontal-Well Completions in Unconventional Reservoirs).

Reverse Cleanout in a Geothermal Well: Analysis of a Failed Coiled-Tubing Operation discusses coiled-tubing operations and the application of a simple hydraulic model to explain possible reasons for ineffective well cleanout. Our final paper on Wells and Production Technology (Some Design Aspects for Venturi Gas Lift Valves) describes, amongst others, the influence of several Venturi valve-design parameters on performance of gas lift valves and provides an analysis of the role of the check valve. The design guidelines provided use data from more than 600 valves run in wells and experimental tests.

We start our discussion of environmental issues in well treatments with a paper discussing Environmental Regulation of Hydraulic Fracturing in Queensland, Australia. This paper presents information supporting the chain of evidence leading to a revision of the Queensland regulations on hydraulic fracturing (expected to be completed and approved in 2015). There is a great deal of useful and pertinent information in this paper, which will be beneficial to all involved in fracturing operations. We then move on to dealing with drilling wastes and a paper that discusses technology to make the waste more benign, specifically the detoxification of two commonly used biocides (Managing Drilling Wastes: Detoxification of Two Formaldehyde-Releasing Biocides). Continuing with our theme on biocides, A Comparison of Three Nonoxidizing Biocides and Chlorine Dioxide in Treating Marcellus Shale Production Waters describes the use of chlorine dioxide, a relatively new addition to oil and gas fracturing, as a biocide. Chlorine dioxide has superior antimicrobial action compared with the currently used nonoxidizing biocides and is more environmentally benign at the low concentrations required.

I hope you enjoy reading these papers as much as I enjoyed selecting them (which meant reading many more papers). I would encourage you to take a look at the Volume Preprint (Online First) section of the journal site because there are many more excellent papers available to read, especially in such straitened times, where training is greatly reduced.

Because this is the final edition of 2015, we are publishing the Technical Editor and A Peer Apart awards lists in this issue. Take a look and see if there are names of colleagues in the list that you might want to congratulate. I would like to add my congratulations to all of those who have received awards. A very well deserved recognition for all.