Ian Collins, BP Exploration
Welcome to the second 2015 edition of the SPE Production & Operations journal. I had a real struggle selecting papers for this issue—there were so many excellent papers to choose from! I finally assembled a selection of papers focused on hydraulic fracturing, a perennial favorite topic amongst our authors, and a series of papers focused on artificial lift and wells technology. This gives a nice breadth of technology across production and operations.
The first paper in this issue is Diagnostic Fracture Injection Tests: Common Mistakes, Misfires, and Misdiagnoses. This paper discusses common issues and mistakes made whilst acquiring diagnostic fracture injection test data. Guidelines on how to avoid these errors and secure the best possible data are provided, including data resolution, pump rates, test duration, and fluid selection. We follow this with a paper investigating the blockage performance of a Cr(III)-acetate-hydrolyzed polyacrylamide (HPAM) gel after placement in open fractures, with an emphasis on the effect of gel maturity during placement [Washout of Cr(III)-Acetate-HPAM Gels From Fractures: Effect of Gel State During Placement). From there, we move onto an excellent case study, Calibration of Well Logs With Mini-Frac Data for Estimating the Minimum Horizontal Stress in the Tight-Gas Monteith Formation of the Western Canada Sedimentary Basin: A Case Study. This paper has as its aim the calibration of well logs with available mini-frac data for estimating the minimum horizontal (in-situ) stress in the tight-gas Monteith formation. Our final paper on fracturing (Diversion Conditions for Viscoelastic-Surfactant-Based Self-Diversion Acid in Carbonate Acidizing) describes the development of a viscoelastic-surfactant radial-acidizing model that simulates surfactant and acid flow, the acid/rock reaction, porosity variation, viscosifying, wormholing, and acid diversion in multiple zones.
We start our exploration of wells technology with some papers describing artificial lift. The first paper, A New Simulation Model for a Beam-Pumping System Applied in Energy Saving and Resource-Consumption Reduction, describes a new comprehensive simulation method for the optimization of a sucker-rod pumping system. The new method combines a slip model of the surface-transmission system with a closely coupled model of the downhole rod-string vibration. We then move on to the subject of rod pumping, with a paper discussing how to optimize the system and save energy (New Secondary Balancing Method Saves Energy for Crank-Balanced Rod-Pumping Application). Energy savings of up to 6.54% are described.
In contrast to field applications, Experimental Study of Centrifugal Pump Handling Viscous Fluid and Two-Phase Flow describes an experimental study about the performance of a centrifugal pump, focusing on the effects of the fluid viscosity and the intake free-gas fraction. The final two papers are focused on well effects. Many wells have the potential to produce more liquid and gas, but the use of tubing anchors in certain wellbore locations chokes the gas flow up the casing and results in increased backpressure against the formation, which restricts production from the well. This issue is addressed in Tubing Anchors Can Reduce Production Rates and Pump Fillage. Finally, the effect of pipe diameter on liquid-loading initiation has been investigated experimentally by the authors of Pipe-Diameter Effect on Liquid Loading in Vertical Gas Wells. The critical superficial-gas velocity corresponding to the minimum pressure gradient was found to be faster for the smaller diameter pipe, and the reasons for this are discussed in the paper.
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 Online First (Volume Preprint) section of the journal on www.onepetro.org/journals, where there are many more excellent papers available to read.
I would like to draw your attention to an upcoming webinar, which provides a great opportunity to obtain some easily accessed training:
Dr. Ghaithan A. Al-Muntasheri: Fluids for Fracturing Petroleum Reservoirs. Register at: http://eo2.commpartners.com/users/spe/session.php?id=15915#
I’m sure that you will be pleased to know that the SPE Production & Operations advisory board is planning on developing themed bundles of webinars from our existing archive that can be offered as a free half-day training event. This is very welcome in the current oil price environment, so watch this space for further news.