In carbonates, the geological facies is a key driver for populating reservoir models with petrophysical properties. Conventionnal core analysis mainly contributes to establish relationships between facies, petrophysics and geophysics. However, populating gridblocks reservoir models with petrophysics requires parsimonious facies classifications and effective relationships at larger scales that field studies rarely investigate. Studying outcrop analogues helps filling the gap between lab measurements and effective upscaled properties of models, and considerably improves the modelling workflows.
The ALBION R&D project developed an innovative framework for multi-physics and multi-scales characterization of Barremian-Aptian carbonates from south-eastern France. These outcropping rudist-rich limestones constitute an analogue of Middle-East reservoirs. Petrophysical and geophysical properties were measured on plugs from cores and outcrops but also at larger scales thanks to original experiments on cores, in and between boreholes. Indeed the analogue includes several experimental areas, where hydraulic tests in sealed wells sections and tomographies between very close boreholes allowed investigating petrophysical and geophysical rock properties at intermediate decimetric to decametric scales. Thanks to the resulting database, this paper aims quantifying the variability of multi-physics data (e.g. porosity, permeability, and P-wave velocity) at different scales in regards of an updated and unified facies classification. The latter is only based on sedimentary origin and fabrics. Other available properties affecting petrophysics are used to cluster facies associations in sub-classes.
Consequently the facies classification does not allow discriminating the distributions of porosity, permeability, nor p-wave velocity. For the rudist facies, that is the most sampled, texture subclasses do not help this work. Reversely, the place of sampling, that is likely a proxy of diagenesis and age, cluster the petrophysical distributions. The results remind us that a proper facies definition should consider both sedimentary origin, fabrics, texture, diagenesis and tectonics. They also point out the relative importance of each characteristics in regards of the scale of interest and the difficulty to infer upscaled relationships between rock properties from CCAL because the representative elementary volume of carbonates is usually higher than the plug and even the core volumes.
Meda, Marco (ENI) | Martinelli, Mattia (Università degli Studi diMilano - Bicocca) | Bistacchi, Andrea (Università degli Studi diMilano - Bicocca) | Mittempergher, Silvia (Università degli Studi diMilano - Bicocca) | Berio, Luigi (Università degli Studi di Parma) | Balsamo, Fabrizio (Università degli Studi di Parma) | Succo, Andrea (Università degli Studi di Parma) | Storti, Fabrizio (Università degli Studi di Parma)
To select the "best outcrop analogue" of a subsurface field/prospect is always challenging, especially when dealing with fractured carbonatic reservoirs. The candidate should match the mechanical stratigraphy, the depositional conditions, the diagenetic history, the tectonic evolution. This is almost impossible, considering that at least the exhumation phase and the associated diagenetic features will not be shared between the outcropping analogue and the buried reservoir. Nevertheless, the analysis of natural analogues can provide useful indications particularly in a complex matter as fracture distribution; in fact, large-scale outcrop analogues reveal their potential when trying to fill the gap between seismic- and borehole-scale structural characterization.
In order to start building an "Atlas of Fracturing Facies" as a digital interactive catalogue of natural fractured analogues, three main cases have been studied: Pag (Croatia) and Parmelan (France) anticlines as analogues for folded and faulted platform carbonates affected by pre-folding extensional faulting, and the Gozo Island (Maltese Archipelago) as an example of carbonatic sequences affected by extensional tectonics. An integrated multiscale approach has been applied, from thin sections to outcrop scale analysis, from drone-based surveys to satellite image interpretation. This workflow leads to the reconstruction of 3D models, and to the quantification of the main parameters characterizing the fracture pattern and its variability.
The Island of Pag, External Dinarides of Croatia, is a thrust-related anticline that involves Upper Cretaceous to Eocene shallow-water carbonate platform sequences affected by tight folding during Eocene – Oligocene times. The fold evolution is multiphase, expressed by pre-folding features developed during a layer-parallel shortening with a strong influence of structural inheritance, followed by fold- and thrust-related cataclastic flow in hinge zones.
The Parmelan Anticline, in the Bornes Massif, Western Alps, is a box-fold involving Lower Cretaceous massive platform carbonates. It is characterized by steeply-dipping limbs, separated by a wide crestal plateau, delimited by narrow hinge zones localized on inherited extensional faults. Its polyphasic tectonic history has been reconstructed by analyzing the fracture and vein pattern, which highlighted the strong influence of structural inheritance during folding.
The Gozo Island is a Late Oligocene-Late miocene carbonatic sequence, composed by platform carbonates with different facies, affected by two extensional events associated to a mult-sets fracture pattern. In Gozo, spectacular coastal outcrops allowed analyzing the structural and statistical relationships between fractures and faults, in terms of density, length, orientation, spatial distribution patterns, and topology.
The Pag, Parmelan and Gozo case studies, together with several literature case studies, are the starting point of the implementation of an Atlas of Fracturing Facies, providing a multidisciplinary knowledge management and data repository platform to improve the prediction of fracture patterns in the subsurface, and its impact on porosity and permeability in reservoirs.
On May 31, SPE International, represented by SPE Executive Director Mark Rubin, extended happy birthday wishes to France's SPE section. More than 350 people were invited by Total E&P to Paris-La Defense to celebrate the 20th anniversary of the French section. This was an opportunity to discuss how the oil and gas industry should face the aging of the industry. Guests from Total, Schlumberger, Gaz-de-France, Stolt Offshore, and IFP took part in the discussion about the coming "big crew change," how to handle it, and how to improve knowledge transmission between experienced people and newcomers. The event also featured the announcement of the creation of an SPE young professionals chapter in France.
The activity of young professionals in France has been growing since the group was launched last May. We are focusing on three axes of development, with different people involved in each. First of all, we are trying to be increasingly involved in the main France SPE section, promoting participation of YEPPs at lectures (two lectures took place during the fall: Reserves Evaluation and Chemical Enhanced Oil Recovery). Two YEPP members are on the steering committee that is preparing a Biarritz YEPP Applied Technology Workshop in March. Second, our section organizes social events (two YEPP "happy hours" since July).
Research Inst., came to Total's headquarters to present a lecture on how human activities are affecting the Earth's climate. Fifty people attended, both young professionals and more-experienced workers, to hear this French specialist who has studied the subject for 15 years. The Earth's climate is warming because of the greenhouse effect, he said. This physical phenomenon has been known since the 19th century, when scientists discovered infrared rays. At that time, Arrhenius predicted that a change in the CO2 concentration in the atmosphere would change the Earth's surface temperature.
The French YP team chose "Challenges of the E&P Industry" as the main subject for its activities in 2006. One of the major events for the YP members was the organization of the third SPE International Young Exploration and Production Professionals' Workshop that took place in March 2006 in Biarritz, France. It was a runaway success, with 48 young professionals attending from 17 different countries. "Our Challenging Future: Preparing Today's Young Professionals for Tomorrow's Challenges" was the overall theme of the workshop. The local YP committee is currently working on the new program for 2007, which will focus on the development of new technical skills.
The French YP Section and SPE Student Chapter kicked off its 2007 activities with a joint event titled "The People Imperative" presented by 2007 SPE President Abdul-Jaleel Al-Khalifa in Paris. Approximately 40 Institute Français du Pétrole students and YPs were delighted to welcome the SPE President. The main subject of his discussion was "What can people do to extend the life of the oil industry?" Senior members of the SPE French Section were in agreement with Al-Khalifa that a remarkable change in both ultimate recovery and finding success can happen only if people develop, deploy, and embrace a new breed of innovation and frontier-breaking technologies.
Summer was eventful for the SPE French Young Professionals (YPs) Section. A new-initiative group was created and is currently working on the new program for the coming year. A New French YP Section was launched in Pau, in southern France. Gerald Latchimy-Parassouramin, 2005–06 SPE Student Chapter president, leads this section. He and four other former members of the student chapter organized a first meeting with YPs in Pau during May.
Hao, Qian (Exploration and Development Research Institute & Science and Technology Department of Changqing Oilfield Company, CNPC) | Wang, Jiping (Exploration and Development Research Institute of Changqing Oilfield Company, CNPC) | Han, Dong (Science and Technology Department of Changqing Oilfield Company, CNPC) | Li, Wuke (Exploration & Development Research Institute of Changqing Oilfield Company, CNPC) | Liang, Changbao (South Sulige Operating Company of Changqing Oilfield Company, CNPC) | Dai, Libin (South Sulige Operating Company of Changqing Oilfield Company, CNPC) | Jia, Yonghui (South Sulige Operating Company of Changqing Oilfield Company, CNPC) | Qi, Congwei (TOTAL) | Zhai, Gaoqiang (TOTAL)
South Sulige operation project is an international cooperation development of tight sand gas field located in the Ordos Basin, Northwest China. The economy of the project relies on technical breakthrough to select good drilling location for getting higher Estimated Ultimate Recovery (EUR) rather than partners continually reducing annual investment and cost saving to survive in the global oil price fluctuations in the long run.
Although a total of 306 wells have been drilled and 1648 Km2 of 3D seismic data have been acquired and processed during the past 3 years, well drilling results were not as good as expected in terms of seismic sand thickness prediction and channel sand / shale discrimination. Seismic data quality indeed improved due to large efforts of the processing, even getting clear seismic images at reservoir level, however, at Upper Permian He8 Formation, the main gas producing target layer, seismic interpretation results are still difficulty to distinguish complicated fluvial depositions of this tight sand gas filed.
On the other hand, existing production data indicate that Absolute Open Flow (AOF) of the super good well which accounts for only 3% of the total drilled wells usually exceed 120×104m3/d, annual production of the super good well could exceed 2500 ×104m3, EUR of the super good well may exceed 2.4×108m3. Compared with the ordinary well, EUR of the super good well is 9.6 times that of the ordinary well. As a result, accurate predicting good drilling location and try to capture more super good wells remains the biggest challenge and the most attractive research direction for this international cooperation project.
Therefore, a different approach joint 3G (Geophysics, Geology, Gas Reservoir) integrated study is carried out by an international joint research team from Paris, France and Xi’an, China. This paper shows a new method of combining sedimentological model from wells results (static data include core description, typical channel E-logs parameters, semi-regional synthesis. dynamic data include AOF, annual production, EUR) with low value of Poisson's Ratio (PR) / amplitude maps which were defined in the study, aiming to identify areas where a given dominant fluvial facies could be predicted.
The paper's objective is to share the integrated study approach to get better understanding of such tight sand reservoir, and the proposed methodology opens new opportunities for predicting good drilling location, increase the probability of capturing more super good wells, lower the project development risk with best practices approach.
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