Source Replacement Techniques:

Transcription

1 SPWLA Nuclear SIG Technical Meeting October The SPWLA Nuclear SIG held a technical meeting on October 9, This meeting was held at Schlumberger s facility at Sugar Land, TX, with R. J. Radtke, SIG VP of Technology and Cornelius Huiszoon, SIG Treasurer, both from Schlumberger, being the primary organizers. Attendance by organizations was as follows: APMI (1), APS Technology (1), Baker Hughes (6), BP (2), Carbo Ceramics (1), Consultants (4), DOE-NNSA (1), ExxonMobil (3), Halliburton (6), PCE (1), Pioneer(1), Schlumberger (15), Shell (1), Starfire Industries (2), University of Houston (1), University of Texas (1), Weatherford (1), and Wireline Truck Fabricators (1). The agenda for this meeting is shown in Table 1 Most of the topics presented in this meeting were considered as off-the-record to get free discourse. The following general comments can be made about the discussion, however: Source Tracking:: Although mobile source security is a very serious matter, progress is being made on ways to track source movement using RF tags and the time-scale at which the move to eliminate nuclear sources from the well site appears to be longer than we had originally thought. This gives us more time to develop alternatives. Logging Industry Landscape: The smaller logging companies supply over 64% of open-hole wireline logging units in the US. They supply service to a variety of applications, government & education, and for mineral, water, and geotechnical logging. In addition to standard density neutron logging, they also perform cased-hole neutron, fluid density and gravel-pack logging using radionuclide sources. Source Replacement Techniques: Considerable progress has been made in improving the density response of so-called source-less neutron-gamma inelastic density tools but these tools still do not provide the same accuracy as conventional tools using Cs 137 for the source (See SPWLA Transactions papers GGG of 2012 and J, JJ, & HHHH of 2014). Some felt an assessment of existing field data will be useful to assess conditions of acceptable applicability of the method. LWD tools of this type appear to have an advantage over wireline tools due to the fact that most of the hydrogen in the borehole has been replaced by the LWD tool body. Some felt that if necessary, D-T sources can now possibly replace Am-Be sources while others thought more work is needed. Considerable progress has been made on increasing D-D pulsed neutron source output from 10 6 neutrons/sec to values approaching 10 7 neutrons/sec. D-D neutrons would exhibit a higher sensitivity to porosity relative to Am- Be while D-T neutrons would exhibit a lower sensitivity (vs. Am-Be). Encouragement was given to continue efforts on D-D development. The above developments, using generators, would not readily benefit the smaller logging companies since they do not at this time have the technical or financial capabilities required to adopt the technologies and advances discussed. They can use help from national labs but only after the technology has been proved viable. Other Technical Developments: The latest generation pulsed neutron spectroscopy tools using LaBr 3 detectors provide a significant step forward in achieving accurate elemental concentrations down hole. There are still serious difficulties in washed out boreholes. 1 Prepared by Dale Fitz, SIG Secretary and supplemented by Ahmed Badruzzaman, SIG Chair.

2 An interesting presentation using pulsed neutron capture tools to track non-radioactive proppant in induced fractures was given. Details of this work can be found in Paper QQQ of the 2013 SPWLA Transactions. Two presentations on fast-forward nuclear modeling to improve formation evaluation were given. Details of this work can be found in Paper FF of the 2014 SPWLA Transactions and Paper of the 2014 IPTC Transactions. The day was concluded with the business meeting that covered two topics: 1) Status and future of the University of Houston Calibration Pits and 2) Nomenclature and standard format for logs. University of Houston Calibration Pits Dr. Badri Roysam gave an update of the status of the UH Calibration Pits. A new engineering building is being built within 30 feet of the gamma ray and neutron pits. Arrangements have been made for the time being to prevent construction equipment from driving over these pits but immediate action is needed to determine the future of these pits. There is now no immediate threat to the KUT pits that are located close to Braes Bayou but their future also needs to be addressed. The University of Houston has expressed interest in having these pits moved to the location of the Petroleum Engineering Special Facilities located on 4500 Gulf Freeway on what used to be the Schlumberger Campus. However, the future of such pits should be such that they are financially self-sufficient and they need to be coupled to an active research program. The casing in the GR pit is in terrible condition and is corroding badly. Consequently, this pit may soon be unusable. There was considerable discussion about developing a compositional and modeling standard to replace the current GR pit. Discussion also covered making new GR calibration pits that will accommodate larger LWD tools and not just wireline tools. There was also discussion about moving the neutron pit. This poses some difficulty since this pit consists of 6 ft. diameter by 1 ft. thick octagonal block that will have to be transported in fluid to avoid desaturation and resaturation issues. Most members seemed to agree that one needed to keep the neutron pit. The following committee was formed to come up with recommendations on what to do with the test pits: Ahmed Badruzzaman Consultant Dale Fitz ExxonMobil Richard Pemper Weatherford Gary Fisher Pioneer Jim Galford Halliburton Greg Schmidt - Schlumberger Gordon Moake - Halliburton Chris Stoller - Schlumberger This committee needs to report back to Dr. Badri Roysam within two weeks on preliminary recommendations. The Committee has begun its work; further input has been received from Dr. Roysam. Note: Nearly 70% of logging units using nuclear sources are in the US and are owned and operated mostly by small companies in Oklahoma and Texas. This needs to be taken into account when considering legislation concerning types of nuclear sources to be permitted in the future and on developing a strategy for the future of the UH calibration pits. Initiatives The SIG document recommending nomenclature to be used for density and P e, developed by Gordon Moake and Dale Fitz, has been reviewed by several committee members. These recommendations are ready to be published in Petrophysics.

3 The recommendations for a standard format for neutron porosity logs have not been completed and work has stopped since Gary Simpson changed jobs. Dale Fitz will pick up this work with help from a couple of others. Ahmed Badruzzaman will forward Gary s notes on this work- Done. Other Items A group photo of the attendees was taken and plans are being made to have this published in Petrophysics along with notes from this meeting. A copy of this photo has already been ed to all participants. Note: The final minutes include changes based on feedback received on the draft. Any remaining errors are inadvertent and are regretted. Please feel free to contact Dale or Ahmed with additional feedback.

4 Table 1. Nuclear SIG Meeting Agenda. Start End Duration (min) Title Presenter 8:15 AM 8:30 AM 0:15 Welcome A. Badruzzaman, Consultant; R. J. Radtke, Schlumberger Moderator: D. Fitz, ExxonMobil 8:30 AM 8:50 AM 0:20 Mobile source security T. Taplin, NNSA-DOE 8:50 AM 9:10 AM 0:20 Alternatives to radioactive sources used in well A. Badruzzaman, Consultant logging and their implications 9:10 AM 9:30 AM 0:20 The impact of non-chemical sources on U. S. well G. Fisher, Pioneer logging 9:30 AM 9:50 AM 0:20 Pulsed neutron generator-driven sourceless F. Inanc, Baker Hughes density measurements expectations, physics and issues 9:50 AM 10:10 AM 0:20 Sourceless neutron-gamma density (sngd): M. Evans, Schlumberger physics principles and applications 10:10 AM 10:40 AM 0:30 Discussion All 10:40 AM 11:10 AM 0:30 Break Moderator: G. Moake, Halliburton 11:10 AM 11:30 AM 0:20 A history of nuclear spectroscopy in well logging R. Pemper, Weatherford 11:30 AM 11:50 AM 0:20 Topics in the interpretation of nuclear spectroscopy J. Grau Schlumberger 11:50 AM 12:20 PM 0:30 Discussion All 12:20 PM 1:20 PM 1:00 Alternatives to chemical sources Spectroscopy Measurements and modeling Moderator: C. Huiszoon, Schlumberger 1:20 PM 1:40 PM 0:20 What is the depth of investigation of open hole G. Moake, Halliburton nuclear tools? 1:40 PM 2:00 PM 0:20 A new nuclear logging method to locate proppant H. Smith, Consultant placement in induced fractures 2:00 PM 2:20 PM 0:20 Nuclear modeling in the service and operating companies P. Guo, ExxonMobil 2:20 PM 2:40 PM 0:20 Fast-forward modeling of borehole nuclear O. Ijasan, ExxonMobil measurements 2:40 PM 3:10 PM 0:30 Discussion All 3:10 PM 3:40 PM 0:30 Break Business meeting Moderator: A. Badruzzaman, Consultant 3:40 PM 4:40 PM 1:00 State and future of API calibration pits at the University of Houston R. Krishnamoorti and B. Roysam, University of Houston 4:40 PM 5:10 PM 0:30 Initiatives: - Standard format for neutron porosity logs - Nomenclature for density and P e All Lunch

5 SPWLA Nuclear SIG Meeting, Houston, Texas October 9, 2014 First Row: Dale Fitz, Jeff Crawford, Gordon Moake, R. J. Radtke, Ahmed Badruzzaman, Jim Galford, Qiong Zhang, Yike Hu, Temeka Taplin, Libai Xu, Sandeep Gade, Jianxing Chen, Badri Roysam (not shown) Second Row: Joe Koudelka, Farid Hamichi, Mathilde Luycx, Jim Grau, Harry Smith, Jiaxin Wang, Qianmei Zhang, Anton Nikitin, Xiaogang Han, Freddy Mendez Third Row: Matt Coventry, Feyzi Inanc, Greg Schmid, Adrian Zett, Weijun Guo, Pingjun Guo, Don Steinman, Avto Tkabladze, Tong Zhou Fourth Row: Toyli Anniyev, Brian Jurczyk, Olabode Ijasan, Cornelis Huiszoon, Chris Stoller, Richard Pemper, Rich Ostermeier, David Rose Fifth Row: Paul Cooper, Simon Hughes, Ron Deady, Ward Schultz, Mike Evans, Scott Fricke, Jack Horkowitz, Gary Fisher, Winston Seaman