6th EAGE Saint Petersburg International Conference and Exhibition

In Cenozoic time changes of vertical and lateral direction of tectonic processes took place within Demyanskiy megaarch and adjoining depressions. Structural trends orientation changed from northwestern to north-eastern and regional down movements gave way to uplifting and partial erosion of previously accumulated sediments. Structural changes of main Jurassic and cretaceous oil-and-gas bearing horizons in Cenozoic time affected hydrocarbons lateral migration pathways and source rocks maturity distribution.

Territory of platform Bashkiria, located on the east end of the Russian platform, in its joint area with Ural orogen, is one of the oldest oil-producing regions of Volga-Ural oil and gas bearing province.

Based on results of CMP-2D seismic exploration works for 2011–2013 years more than 5 thousand linear km. of lines were acquired, 117 wells were prospected, which uncovered the Riphean sediments within the territory of Bashkortostan Republic. This allowed us to revise the geological model, fault-block tectonics and to allocate prospective objects, where it is recommended to carry out detailed seismic works for the purpose of the given structures composition revision with further recommendation for drilling exploration wells.

In western and north-western parts of Bashkortostan Republic territory from the south to the north – Ivanovsky high is worth noticing.

In the central part of Bashkortostan Republic territory Birsky high and Kushkul structure of inversion type are of the main interest. In eastern and north-eastern parts of the platform territory the South-Tavtimanovskaya closure is of a prospecting interest along the Riphean sediments, being the main element of Arov-Kultubinsk anticline.In the south-east of the territory Arlarovsky and Kulguninsky highs are worth special noticing.

In the report is shown the attraction of detailed litological, petrophisical and geochemical researches of a representative core data can be used for a problem definition at interpretation of GIS and 3D seismic and promote to increase quality of geological model of the Bazhenov formation. Relevance of approach is defined by that many methods of work with traditional reservoirs weren’t applicable to the Bazhenov reservoirs. Researches of a large number of fields with the proved efficiency of deposits of the Bazhenov formation located within various tectonic elements of Western Siberia, carried out by a uniform technique, allow to study and compare features of such fields, to prove similarity or distinctions like their oil-bearing capacity, a structure of reservoirs and the dominating factors defining degree of efficiency of this strata.

The study of fractured reservoirs clay using seismic data is a complex task. Modern applications (Multi-Wave Seismic, Tectonophysical Modeling, PRONY-Filtering) do not predict the oil-productivity directly, but simply engaged in mapping of fracture zones.

In the fractured clay reservoirs a large heterogeneity of clay deposits means the formation of fractured zones. These zones represent potential reservoirs of oil with increased productivity. To estimate it authors proposed to use the Capacitive Differentiation Factor (CDF). CDF is the ratio of the total productive capacity of fractured reservoirs clay to the total capacity of reservoirs, which have the capacity in two and more times higher than the average capacity of the target interval.

In the innovative technology of spectral-velocity prediction (SVP-technology) the method of prediction of oil-productivity of fracture clay reservoirs is implemented. The Spectral-Time Attributes are well correlated with the CDF and the CDF - with the oil-productivity.

The described method was tested for studying the Bazhen deposits in Western Siberia. The described method for predicting of fracture oil-productivity clay collectors on the basis of Spectral-Time Analysis of the seismic record is innovative and has high confirmability of subsequent drilling.

Shale gas reservoirs are fine grained organic rich formations which act as source as well as reservoir rocks. Typically, shale matrix permeability is very low and requires additional stimulation treatments for economic production.

This work focuses on the characteristics of shale gas reservoirs and production activities worldwide with a special focus on Germany. A brief overview of the major shale gas basins in different countries of the world is presented along with their major reservoir properties.

The geology of the shale gas reservoirs is discussed in detail. Also, emphasizes has been laid on the study of the important reservoir properties of shale gas reservoirs and different methods used both in field and laboratory to measure these reservoir properties.

This work provides an insight into the Hydraulic fracturing, horizontal drilling and the equipments used for production from shale gas reservoirs.

A comparison of the different rock properties and production profiles from different shale gas reservoirs of the world is done and a table is prepared for economic production of shale gas reservoirs.

Finally, the simulation of one of the Barnett shale gas well is carried out and production profile of the well is analyzed and the results are discussed.

Methods for determining properties of shales from cuttings samples are beneficial as they provide a fast and cost-efficient way for evaluating potential shale reservoirs for which often core sample data and modern wireline logs are missing. A case study is performed on 80 cuttings samples from the radioactive Silurian shales of a Palaeozoic basin in SW Algeria. In this study geochemical (Rock-Eval pyrolysis and LECO carbon analysis), mineralogical (QEMSCAN analysis), structural (CT scanning) and geomechanical (nanoindentation) analyses are performed on cuttings samples to characterize the heterogeneity of the shales and predict shale gas sweet spots. Using these innovative analysis methods reliable values for the properties of the radioactive Silurian shales are obtained. By integrating TOC content values and QEMSCAN data with wireline logs, clear vertical trends/cycles are identified and the strong vertical and lateral heterogeneity of the shales is demonstrated. Using CT scanning different fractural networks are observed and Young’s modulus values obtained from nanoindentation measurements are in the range expected for shales (± 33 GPa) and are appropriate for shale gas production. The shale gas opportunity is confirmed for the radioactive Silurian shales and sweet spots are indicated by high TOC contents and favorable mineralogical compositions and geomechanical properties.

Mineless exploration technology is developed for extraction of hard-to-reach mineral resources presented by thin productive stratums within the fields of any complexity factor.

This paper presents the general geochemical characteristics of Silurian shale with the aim to constrain its shale gas potential in Poland.

Estimating the reserves in shale type reservoirs required more interdisciplinary treatment than the works devoted to this subject in conventional reservoirs. In evaluation presence of water and oil in the pore space must be taken into account consideration. The next problem is possibility of existence of pore space in organic matter. Not only free gas existed in such type of pore space but also absorbed one, so in the calculations a ratio absorbed to free gas must be included.

The most important in shale gas investigations are geochemical works, with the usage of rocks samples as well as gas samples, from degasation of cores and from reservoirs. These type of investigations makes it possible to execute a quantitative evaluation GIP (Gas in Place), and the same calculation of reserves of gas. The first of all should to determine the content of organic matter and thermal maturity level, which is crucial for selecting the sweet spot for shale gas. All these estimations could be made on the basis of archival data as well as recent ones from newly drilled bores.

The report shows the methods of criterion analysis of geological and production data. These methods justify the reasons of the high water cut, wells selection for the forced production, lateral holes drilling, increase well productivity, optimize the system to maintain reservoir pressure. Particular attention is paid to ways to create an array of wells that require evaluation of the causes of deviation from the targets activities. The data for evaluation of technical efficiency activities are obtained by performing calculations of each variant of oil, fluid production, and the energetic state of wells in the space of 3D. Interference effects of wells and filtration flow changes both increase or decrease production of individual wells. Therefore the estimate of the effect of measures performed only in wells which held EOR gives overestimate. The methods of performance evaluation systems to maintain reservoir pressure are discussed. The report shows methods of technological and economic evaluation of different EOR methods. Analysis and methods are presented in this report were used to enhance production of mature oil fields in Russia and abroad

Petroleum industry welcomes new drilling technologies that not only decrease oil and gas wells drilling costs but also increase rate of penetration. Entry of new advanced technologies to the oil and gas industry in the countries having hydrocarbon resources led them to improve their position in the world, likewise moving toward greater profitability. Abandonment of traditional methods and good infrastructure for research and development of new technologies could be the key to advancing this industry as well as reducing the related heavy costs. According to the statistics, in the drilling of a well 48% of time spent on drilling from surface to the reservoir, 27% spent for bit replace and casing running, and 25% spent for logging while drilling. The methods which could be reduce the time of drilling, and bit replacing time would be very effective in reducing the costs. Our experiments demonstrated that the laser drilling method is the best way for saving in time and cost in oil and gas wells drilling and completion.

Moreover, results shows we can imaging many applications of laser beam in petroleum industry such as, laser perforation, mud cake removal, and create the windows in order to production of multilateral layers.