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Timonin A.,Schlumberger | El Battawy A.,Schlumberger | Kubekbayev I.,KMG EV | Pakozdi G.,MOL
Society of Petroleum Engineers - SPE Annual Caspian Technical Conference and Exhibition | Year: 2014

In a gas-condensate field in Kazakhstan, advanced production logging tools and techniques were used to assess well productivity, characterize flow profiles, and determine hydrocarbon saturation pressure at downhole well flowing conditions. The exploration and appraisal wells produce from a complex carbonate reservoir. To assess well productivity, each well was perforated and tested across each formation separately. Intervals to perforate were selected based on petrophysical log evaluation, core analysis, and the results of selective testing with a wireline formation tester. While testing these wells, production logging data were acquired at different downhole flowing pressures and a detailed analysis of gas holdup measurements with optical probes enabled the determination of the dew-point pressure of produced gas-condensate. Such analysis is beneficial, especially when pressure/volume/temperature (PVT) analysis of produced fluid is not yet available for exploration and appraisal wells. Further comparison of wireline-acquired PVT samples showed good agreement between measured dew-point pressure from the production logging tool and PVT laboratory analysis results. In the field, production logging helped in understanding well behavior by locating producing intervals in wells that have more than one perforated interval or produce from only one long perforated interval that has several producing intervals. Field experience verifies that a properly planned and executed production logging operation can yield invaluable early information for key investment decisions and complement the results of the well test. Copyright 2014, Society of Petroleum Engineers. Source

Palotai M.,Eotvos Lorand University | Csontos L.,MOL
Central European Geology | Year: 2012

Several main tectonic lineaments originating in the Alps and Dinarides merge in Central Hungary to form the Mid-Hungarian Shear Zone. As these structures are hidden beneath sub-basins of the Neogene Pannonian Basin, it has long been debated whether the tectonic style of the shear zone is mainly contractional or strike-slip. New 3D seismic data allowed a detailed analysis of one of these sub-basins, the Adony Basin, located south of Budapest. Its evolution is linked to the tectonics between the southern Tisza unit of European passive margin affinity, the northern ALCAPA block with Alpine affinity, and sheared remnants of Dinaric units in between. During the Oligocene and Early to Middle Miocene, a flexural basin related to the convergent thrusting of Dinaric-and ALCAPA-derived units was developed. On the southern side, N-NW verging thrust sheets were observed. On the opposite front, Triassic carbonates of ALCAPA were thrust several kilometres above Palaeogene formations to the SW. Dextral transpression is assumed for the Middle Miocene. Local deposition of Middle Miocene salt in the basin formed a detachment surface. Late Miocene sinistral strike-slip faulting resulted in a pull-apart basin above that part of the earlier flexural basin that has not been overthrust. The margins of the basin coincided with the fronts of earlier thrusts. Faults on the basin margins partly detached on the salt, decoupling the supra-salt basin fill from the underlying formations. Within the pull-apart basin, gravity sliding on the steep margins resulted in salt welds, detachment and roll-over folds. Source

El Battawy A.,Schlumberger | El Khatib K.,MOL
Society of Petroleum Engineers - SPE Arctic and Extreme Environments Conference and Exhibition, AEE 2013 | Year: 2013

With today's economic realities, operators realize the value of attaining information about reservoir potential as soon as possible. The early confirmation of new reservoir potential can translate into time and money savings and can support decisions to optimize the well testing program and plans to drill new wells. Case studies from appraisal wells in a carbonate gas condensate reservoir located in north Kazakhstan illustrate the importance of real-time information. In these wells, the use of wireline formation tester (WFT) interval pressure transient testing (IPTT) coupled with the latest generation fluid analyzer provided fluid properties and reservoir characteristics and confirmed the presence of additional reserves. When the reservoir was discovered, operational considerations precluded the immediate acquisition of well test data. As a result, the operator had to proceed with significant economic decisions based only on the acquired WFT data. A full year elapsed before the well test results confirmed the initial WFT results. The IPTT uses two inflatable packers to isolate a borehole interval for testing. A downhole pump is used to clean up invaded filtrate and flow reservoir fluids during fluid cleanup, while composition and gas/oil ratio are measured using a fluid analyzer. After collecting pressure/volume/temperature (PVT) samples, a pressure buildup is performed, and transient pressure data are analyzed for the permeability-thickness product and skin factor. Two different formations were investigated with WFT IPTT and a full drillstem test (DST). The fluid properties measured in real time matched later PVT laboratory analysis and wellhead production. Reservoir characteristics from both interpretations were in close agreement. The well test, with its deeper depth of investigation, detected a fault boundary that was not seen on the WFT IPTT. The field examples showed how a judiciously planned and executed WFT acquisition can provide invaluable early information for key investment decisions and complement the design of the well test. Copyright 2013, Society of Petroleum Engineers. Source

Hancsok J.,University of Pannonia | Kasza T.,University of Pannonia | Kovacs S.,University of Pannonia | Solymosi P.,University of Pannonia | Hollo A.,MOL
Chemical Engineering Transactions | Year: 2011

The production possibilities of gasoil boiling range mixtures of paraffins were investigated over different catalysts as a function of the process parameters using different natural triglycerides. At the favourable operational parameters (T: 360-380°C; p: 60-80 bar; liquid hourly space velocity (LHSV): 1.0-2.0 m3 feedstock/m3 catalyst · h; H 2/HC: 450 Nm3/m3) the yield of paraffin mixtures increased in the order of NiW/Al2O3 < NiMo/Al2O3 - CoMo/Al2O3. in the best cases the yields of paraffins reached 75-85% of the theoretical values. These compounds are excellent fuels of Diesel engines (cetane number: 89-92) using them as pure fuels or blending components. Copyright © 2011, AIDIC Servizi S.r.l. Source

Urraca M.,Schlumberger | Balazs I.,MOL
72nd European Association of Geoscientists and Engineers Conference and Exhibition 2010: A New Spring for Geoscience. Incorporating SPE EUROPEC 2010 | Year: 2010

Based on European Union (EU) Directive 2003/55/EC and Hungarian energy regulator "Magyar Energia Hivatal" requirements, Hungary must have sufficient gas reserves to satisfy a full month's household demand. Although five commercial underground gas storage (UGS) fields were operating in Hungary by 2007, a higher rate of gas production was needed. For this reason, the Hungarian government decided to develop a new UGS field rather than to increase the capacity of the existing ones. Because of favorable reservoir characteristics, Szoreg field was selected, and 44 wells were scheduled to be drilled in VA years. Tight drilling and completion schedules, the operating company's turnkey contract terms, and a fixed budget made critical the success of primary cementing jobs with fit-to-purpose systems and without the occurrence of any type of remedial work. The drilling plan included 34 vertical or deviated wells and 10 horizontal wells, each with 3 casing strings and gravel-packed completions, with the cementing objectives to provide a top of cement to surface for every casing string. For the last cemented (reservoir) casing, the presence of two sands with a marked difference in formation pressure and separated by a shale cap of only 4 m to 7 m in length required perfect zonal isolation. Depleted and unconsolidated formations required the use of lightweight slurries to reduce hydrostatic pressure on the formation. For further losses prevention and minimization of formation damage deep in the reservoir, engineered fiber material (EFM) was programmed in the cement slurry based on drilling events. Furthermore, an analytical model showed that the cement sheath located between the casing and the reservoir would be exposed to injection and production cycles with high pressure and temperature differentials which demanded a cement system with sufficient flexibility to withstand the mechanical stresses and to optimize expansion to prevent microannulus creation. Despite the technical and budgetary challenges, methodical planning, the use of new technologies, and engineered optimization resulted in a successful cementing campaign with the required zonal isolation achieved within the project budget limits. © 2010, European Association of Geoscientists and Engineers. Source

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