Below is a list of basins and fields; however this is a short list since there are more than 65,000 oil and gas basins and fields of all sizes in the world. However, 94% of known oil fields is concentrated in fewer than 1500 giant and major fields. Most of the world's largest oilfields are located in the Middle East, but there are also supergiant ( 10 billion bbls) oilfields in India, Brazil, Mexico, Venezuela, Kazakhstan, and Russia. Add any basins or fields that are missing from this list!
Investigation of the permeability of carbonate rocks is essential and challenging due to the heterogeneity of carbonates at all scales. At the micro-scale, pore geometry, pore size distribution, and pore connectivity are important factors controlling permeability. This study focuses on the influence of pore size distribution and pore structure on permeability to better understand the fluid flow in carbonate rocks.
In this paper, we use micro-computer tomography (micro-CT) to capture the microscopic heterogeneity in the pore structure. Firstly, we collected seven 1 x 6 inch carbonate rock samples including Indiana Limestone, Desert Rose, and Travertine with various porosities and permeabilities. The porosity was measured gravimetrically, and permeability was measured with core plug flooding experiments. Cubic centimeter size core samples were scanned with enhanced micro-CT imaging with the resolution of 6-8 μm/voxel, then scanned 2D images were processed with image processing software to distinguish the pore system from the matrix. The pore size distribution for each rock sample was determined by fitting a statistical function based on the binarized images. We defined a concept of equivalent pore radius to characterize the pore system, which effectively filters out the non-contributing small pores and preserves the pores actually contributing to fluid flow. The relationship between the equivalent pore radius of each rock and permeability was investigated. Based on the 2D image stack, we also constructed the 3D pore network to observe the pore structure, quantify connectivity and specific surface ratio to study their influence on permeability.
We found that laboratory measured permeability from core plugs was strongly correlated to the equivalent pore radius calculated from micro-CT scanned images among the investigated carbonate rock samples. The semilogarithmic correlation between permeability and effective pore radius fit the measured permeability data very well over a permeability range of more than two orders of magnitude. The findings of pore-scale pore structure and pore size distribution in this study are helpful for carbonate rock analysis, and the proposed new correlation between equivalent pore radius and permeability is practical for permeability estimation for a wide range of carbonate rocks.
Rojas, Pedro A. Romero (Weatherford International) | Cristea, Alexandrina (Weatherford International) | Pavlakos, Paul (Weatherford International) | Ergündüz, Okan (ARAR AS) | Kececioglu, Tayfun (ARAR AS) | Alpay, Server Fatih (ARAR AS)
Nuclear magnetic resonance wireline logging and data post-processing technologies are continuously evolving, making significant contributions to rock, fluid typing, formation evaluation and characterization of the near-wellbore zone. In heavy oil fields, however, nuclear magnetic resonance (NMR) logging is known to provide an underestimated permeability, poor reliable oil typing and thus poor oil saturation and viscosity determinations, especially when the evaluation is based only on the spectra of transverse magnetic relaxation times (T2) (one-dimension NMR) [Romero et al., 2009]. Several attempts have been made to improve NMR results, mostly with limited success [Fang et al., 2004], especially in separating the oil component from the contribution of other fluids to the T2 spectra. The main reason lies not necessarily in the selection of the data acquisition parameters and sequences for a single-frequency or multi-frequency tool, but in the way how the data is post-processed.
The present study refers to a well drilled through the Derdere formation, a limestone/dolomite heavy oil reservoir in Turkey. The NMR data was acquired in with a centralized, single-frequency wireline tool in a 6-in. borehole, drilled with water-based mud in a freshwater carbonate reservoir. The generated T2 log was analyzed in a traditional way to obtain the NMR total porosity and its partitions based on standard cutoff values. For the given 12 API oil gravity, reservoir temperature (76 °C) and gas-oil-ratio (GOR) the T2Oil peak appears around 170 ms, right from the T2 cutoff for limestones; therefore, no corrections were needed on the permeability calculated from the Timur-Coates and Schlumberger-Doll-Research (SDR) equations. In the present well, only a diffused separation between oil and free water could be observed on the T2 distribution log from field data.
In the broader concept of Artificial Intelligence, the newly proposed post-processing steps to obtain the oil saturation start by deconvolving the T2 spectra, using blind source separation (BSS) based on independent component analysis (ICA) [Romero, 2016; Romero Rojas et al., 2018]. Based on its T2 peak value —the expected T2Oil peak response— calculated from the prejob planner/simulator, the deconvolution results show that one specific independent component corresponds to the oil, from which the oil saturation was determined.
Results demonstrated the usefulness of NMR logging technology in the characterization and evaluation of this reservoir. Data post-processing based on BBS-ICA enable adequate differentiation between fluid components from T2 spectra. For the reasons above, NMR has been proposed for additional wells in the same field.
The SPE North America Student Symposium is a massive conference put together by SPE International Students across North America. This year, the SPE North America Student Symposium will be held in conjunction with the North America Petrobowl Regional Qualifier. The SPE North America Student Symposium is an annual student conference organized by SPE International students across North America. The Symposium presents an opportunity for students to enhance their knowledge of the oil and gas industry through the insights and experiences of industry leaders and advocates. It also provides attendants with a myriad of networking opportunities, as students, faculty, and industry experts from around North America will be participating.
Long-term studies of oil spill responders are urgently needed as oil spills continue to occur. To this end, the prospective Deepwater Horizon (DWH) Oil Spill Coast Guard Cohort study was established . DWH oil spill responders and nonresponders who were members of the US Coast guard were included. A team of researchers from the University of Houston is working with the oil industry to develop new ways to predict when an offshore drilling rig is at risk for a potentially catastrophic accident.
UK's First Carbon Capture and Storage Project Could Be Operational by Mid-2020s The Acorn Project will capture about 200,000 tonnes of carbon dioxide from the St. Fergus Gas Terminal and transport it for storage to one of three depleted gas fields using existing pipelines. Levels of stress and mental health problems among UK workers are at a 17-year high, according to the latest injury and ill health statistics published by the Health and Safety Executive. The UK’s offshore oil and gas industry continued to see improvement across a broad range of health and safety indicators last year, according to a key insight published by Oil & Gas UK. Offshore Industry Has Come'Perilously Close to Disaster,' Warns UK's Health and Safety Executive The Health and Safety Executive (HSE) has warned the UK’s offshore oil and gas operators that they must do more to tackle hydrocarbon releases in the North Sea after coming “perilously close to disaster” in recent years. Oil & Gas UK recently published guidelines with its most up-to-date information aimed at helping operators ensure they have the required financial measurements in place to meet the cost of cleanup for an oil release. North Sea oil and gas production was up but greenhouse gas emissions in 2016 were down against 2015 performance, according to Oil & Gas UK’s Environment Report.
Emmanuel Ikehi, Richard Boakye Yiadom, David Semwogerere, and Lotanna Ohazuruike are this year’s recipients of the Imomoh Scholarship, which was endowed to the SPE Foundation by Egbert Imomoh to support excellence in education for students from Africa. In 2013, Ikehi served as a petroleum engineering intern at the Nigerian Petroleum Development Company. His journey to the Imomoh Scholarship began in 2012 when he inspired his course mates to form an SPE student chapter. He went on to become the pioneer secretary of the newly formed chapter. Since then, he has been an active member of SPE.
He has been awarded the 2011 Henry Dewitt Smith Fellowship. He is awarded the 6000 USD fellowship. Gerrit is pursuing a Master’s degree in petroleum engineering at The University of Oklahoma, USA. He also completed his undergraduate degree at The University of Oklahoma, graduating summa cum laude. He is fluent in English and Dutch.
Aygyul Telyasheva is a PhD candidate concentrating on process chemistry of fuels and high energy substances. She is also the president of the SPE student chapter of the Ufa State Petroleum Technological University (USPTU) in Russia. She completed her undergraduate degree in chemical technology of natural energy carriers and hydrocarbon materials at the USPTU and graduated summa cum laude from this program. Telyasheva is fluent in English and Russian. During her undergraduate and graduate studies, Aygyul’s overall mark was a perfect 5.0, and the best among all students in Russia.
Mr. Kalantari-Dahaghi is a PhD student in Petroleum & Natural Gas Engineering at West Virginia University. Amirmasoud received his BS in petroleum engineering from Petroleum University of Technology and MS in petroleum and natural gas engineering from West Virginia University in 2010. His current research interests include modeling & simulation of shale gas reservoirs and computational Intelligence application in shale gas modeling. He played a coordinating role in several shale gas projects in Petroleum Engineering & Analytics Research Lab. (PEARL) at West Virginia University. Amirmasoud has published several technical papers and has presented in SPE conferences and also served as a technical reviewer for several SPE and other petroleum engineering related journals.