«OIL AND GAS GEOLOGY» № 5/2017
Geologiya Nefti I Gaza" ("Oil And Gas Geology") is included by the Higher Attestation Commission in the list of leading scientific journals and publications where the main scientific results of dissertations for the degree of candidate and doctor of sciences
Editorial office address: 36 shosse Entuziastov, 105118, Moscow, Russia
Viktor Petersilie, deputy editor-in-chief
OIL AND GAS POTENTIAL AND GEOLOGICAL EXPLORATION RESULTS
V.I. Bogoyavlenskiy, I.V. Bogoyavlenskiy, O.V. Bogoyavlenskaya, R.A. Nikonov. Oil and gas occurence prospects of the Circum-Arctic sedimentation basins and basement
For the first time complex analysis of shelf and deeper zones of Circum-Arctic megabasin oil and gas potential based on new onshore and offshore geological, geophysical and geochemical studies was conducted. The models of different-aged acoustic basement and sediment cover thickness were specified. The scheme (map) and regional cross-sections of source rocks catagenetic transformation for on- and offshore oil and gas bearing basins and potential of Russia, Norway, Denmark, Canada and USA were designed. Defined that the source rocks of lower sedimentation level are in meso- and apocatagenesis zones what gives a possibility to state the presence of productive intervals in oil and gas windows of HC generation. High HC potential of the Arctic shelf (South-Chukotka, Novosibirsk-North-Chukotka, North-Kara, Anabar-Laptev, East-Greenland and Lincoln), deeper troughs (Canadian, Podvodnikov and Nansen) and continental margin were proved. Potential oil and gas bearing zones in crystalline and consolidated basement are identified in the Arctic Eastern Hemisphere based on Southern-Chinese Sea crystalline basement HC potential research. The results improve the effectiveness of large HC fields prospecting and development in the Arctic.
V.V. Shimansky, I.S. Niziaeva, N.V. Taninskaya, N.N. Kolpenskaya, N.Ya. Vasiliev, M.A. Miasnikova, V.N. Zeltser. Oil and gas deposits sedimentation model of Vasyuganskaya suite of Latitude Priob northeastern region
Integral studies of the Vasyuganskaya suite deposits sedimentology in the northeastern part of Latitude Priob region have been carried out based on core detailed analysis from 62 wells and facies interpretation of well logging data on over 1000 wells. Sedimentological and ichnofossil facies core analysis, lithological-petrographic studies and paleo-structural reconstructions have been performed. The work was conducted using both standard methodology and author's methods of sedimentation modeling developed in the AO “Geologorazvedka”. Lithofacies and 25 lithogenetic rock types have been identified and conditions of their formation have been reconstructed. Also, sedimentation environments determined and facies sections and maps were compiled. Sedimentation model has been created for the productive strata formation of the Vasyuganskaya suite. The conclusions derived are as follows. Sediments for Layer J accumulated during the Callovian time mainly in marine environments of open sea shelf. Between the Callovian and Oxfordian times a regression is noted. The silt-sand J Layers of the Upper Vasyuganskaya sub-suite were formed under conditions of primarily submarine and then emerged delta plain. Formation of Layer J in the Middle Oxfordian time during the delta progradation under conditions of submarine delta plain was accompanied by formation of the proximal, middle and distal parts of the delta and prodelta fans. In the Late Oxfordian time (Layer J) during the sharp drop of sea level and further progradation of the delta, vast delta sequences spread over most of the study area. The final stage of the delta progradation is characterized by advent of alluvial plain environments in the central and eastern parts. During the Late Oxfordian time at the top of the Vasyuganskaya suite a transgressive surface was formed all over the area and the conditions of sedimentation abruptly changed for shallow-water marine environments.
F.A. Migurskiy, E.M. Yakupova. New data on the geological anticlinal structures of the nothern part of Predverkhoyanskiy pericratonic foredeep
In 2014 –2016, for the purpose of geological study of the northern part of the Pred-Verkhoyansk pericratonic foredeep located on the eastern outskirts of the Siberian platform, the 2D CDP seismic surveys with total operation volume equal to 1800 km were carried out. The Setasskaya anticline, known as one of the most contrast and just slightly faulted structures, is crossed by seismic Line 140304A. Interpretation of the new Lines (140308, 140307 and 140305), well logging data and stratification of sections of Diappalskaya-1 and Govorovskaya-1 wells sections permitted to update the geological structure of the Setasskaya anticline. For the purpose of assessing the oil and gas potential an important result is the confirmation of the Riphean, Vendian and Cambrian sedimentary strata occurrence. In adjacent areas the Cambrian deposits contain slightly transformed oil and gas source rocks (black shale rich in organic matter). Within the anticline these rocks may happen to be in the main oil generation window. In the article the identified trap structure is shown to be related to the overthrust-adjacent dislocations. The important role of backthrusts is revealed. Depths of the promising units occurrence are specified and conclusions on the most prospective part of the structure are drawn. Based on the results of the study, recommendations are given for spudding the Setasskaya-1 parametric well on Line 140304A.
HC HARD-TO-RECOVER RESERVES AND UNCONVENTIONAL SOURCES
T.K. Bazhenova. Comparative analysis of bituminous formations in Russia due to hydrocarbon resources estimation
Bituminous formations of Russian continental part are comparatively analyzed in the article considering their oil production possibilities; their characteristics regarding concentration of CNL, biocenotic composition and OM catagenesis are given. The total amount of generated oil and its migrated and residual constituting parts are calculated for each formation. Brief information on oil accumulations and oil manifestations within these strata is also given. The Bazhenov suite J3 occurring in the West Siberian plate holds the first place minding the extent of oil generation; the D3 formation developed in the East European Platform ranks the second and the third position is occupied by the Kuonam suite C1-2 located in the East of the Siberian Platform. Bituminous strata of less importance are as follows: Malginskaya and Iremekenskaya suites in the Riphean of the Siberian Platform; Lower Silurian graptolite shales occurring in the Siberian Platform and the Kaliningrad Region; Kumskaya and Hadumskaya suites of the Paleogene age in the Pre-Caucasus and siliceous sequences of the Oligocene – Miocene in the Okhotsk Sea region. The total quantity of oil generated in these strata is equal to 10782 billion tons, the total emigrated and residual oils amounting to 7460 billion tons (69.2 %) and 3321 billion tons (30.8 %), respectively.
A.I. Varlamov, V.I. Petersilye, V.I. Poroskun, N.K. Fortunatova, N.V. Komar, A.G. Shvets-Teneta-Guriy. Technique of oil reserves estimation in Domanik deposits
Oil reserves calculation by traditional volumetric method is not applicable to the domanik type deposits because of abnormally low reservoir properties (their storage capacity and, especially, fluids transmissibility). A new approach proposed for the reserve evaluation is based on identification and assessment of oil-saturated intervals porosity. The oil pool limits are proposed to be determined taking into account the lateral continuity of the domanik type rocks and the level of geological knowledge on the license area. Oil recovery factor is the most ambiguous parameter used in oil reserves evaluation in rocks of the domanik type. Its value for oil pools under development is proposed to be accepted on the basis of development results in accordance with technological documentation of the field development plan. Any strict methodology of recovery factor determination for oil pools in rocks of this type does not exist. For such pools it is proposed to accept the oil recovery factor value conditionally equal to 3 % when using the technology of multiple hydraulic fracturing.
G.F. Ulmiskek, A.V. Shalomeyenko, J.E. Holton, M.V. Dakhnova. Unconventional oil reservoirs in the Domanik formation of the Orenburg region
The arti cle presents the results of study of the unconventi onal Domanik reservoirs where two specifi cally targeted wells were recently drilled on the Kashaev license block in the Orenburg Region. On the block, the Domanik formati on 350–400 m thick includes the strati graphic interval from the Middle Frasnian to the Tournaisian Stage. The formati on is composed of two main types of rocks: (1) black, calcareous, in places radiolarian chert and (2) gray and dark gray thin‑grained, partly siliceous limestones. The content of clay minerals in all Domanik rocks is low (< 10 %). The rocks were deposited in an oxygen‑starved, hydrologically stagnant, deep water basin. Original organic matt er of Domanik rocks was almost enti rely composed of type II oil‑prone kerogen. The total organic carbon content in highly siliceous rocks reaches 18–20 % and averages 3.7 %. The average for limestones is 1.9 % with the range of 0.1 to 4.4 %. All Domanik rocks are oil‑saturated; apparently no free water is present. Reservoir properti es of Domanik rocks are poor. In the best intervals, eff ecti ve (not fi lled with bitumen) porosity reaches 6.0–8.4 %. Permeability is in a range of a few hundred ths to 0.1–0.2 md. Because of extensive oil saturati on and absence of free water oil accumulati ons in Domanik rocks are of conti nuous type; they are not controlled by local traps and can cover large areas. Oil pool may be understood as a bed or a group of beds that are characterized by bett er reservoir properti es, especially porosity, and are capable to commercially produce oil. Producti on from such reservoirs usually requires horizontal drilling and hydrofracturing.
А.P. Afanasenkov, M.T. Bondarenko, I.K. Kondratyev, A.N. Obukhov, Yu.M. Kissin. Identification and detalied study of HC prospects in the Yenisei-Hatangskaya and Gydanskaya oil and gas areas using stratum inversion of seismic data
The frontier areas of the Siberian platform northern margins, especially the Yenisei-Khatangskaya and Gydanskaya oil-and-gas areas, became the scene of intensive activity within the governmental program in recent years. Over 20 thousand km of seismic lines have been shot and interpreted, which permitted to update and expand bank of structural maps, carry out HC resource potential re-evaluation, identify prospects and to pinpoint sites for parametrical and exploration/assessment drilling. Some innovative technologies were successfully applied for solving these problems, including the detailed interpretation of seismic data based on the stratum acoustic inversion by means of optimization of the dynamic interpretation technology. The system work results in the region of the Rassokhinsk and Balakhninsk mega-swells within the Yenisei-Khatanga regional deep, as well as in the vicinity of the Utrenneye field in the North of the Gydansk Peninsula are demonstrated. The obtained seismic-acoustic sections (sections of stratum velocities) incorporate deposits of the Jurassic – Cretaceous terrigenous sequence. On these sections reservoir beds are identified as follows: sandy reservoirs in the Tanopchinsk and Nizhnekhetsk oil-bearing suites of the Lower Cretaceous, and promising reservoir beds in the Malyshevsk, Vymsk and Sharapovsk suites of the Jurassic. The presented data of the optimized technology of dynamic interpretation was used in the detailed study of zones and sites suitable for locating parametric and deep exploration wells.
G.S. Kazanin, G.I. Ivanov, A.G. Kazanin, E.S. Makarov. Innovative vector of Russian marine geophysics development
New technologies used in conducting offshore geological prospecting operations are considered in the article. In a way these technologies set up a "new vector” for development of the domestic geophysics. Today, when talking of competitiveness of the Russian marine geophysics, the work done by JSC “MAGE” can be named as a vivid illustration of the study conducted at a state-of-the-art scientific and methodological level in the most difficult climatic conditions of the Arctic Region. Over the past few years the company has developed and introduced innovative technologies including sub-glacial marine seismic operation, multi-component seismic surveys in transit zones and geophysical observations in the process of engineering and geological surveys. For the first time in the World history the company managed to perform the whole set of geophysical studies (refraction, reflection and CDP seismic, gravity, seismic side-scanner) across the North Pole and thus obtain new information on structure of the central deep-water part of the Arctic Ocean owing to use of sub-glacial seismic exploration technology developed by the company. Use of the 4C technology with bottom stations provides for a gradual transition to the multi-wave seismology. The integrated technological cluster of seismic operations on the sea shelf, transit zone and land with high quality of seismic recording allows for a seamless mapping of the most promising areas on the Russian shelf. Use of the high and ultra-high resolution seismic for detailed stratification of the section upper part aimed at detecting gas "lenses" and gas-hydrate pools, as well as predicting the shallow accumulations of gas in the upper part of the section, provides a reliable and effective basis for the development of oil and gas fields on the shelf.
A.D. Saetgaraev, I.Yu. Khromova, N.Ya. Marmalevsky. Identification of vertical reef-related formations walls by the duplex wave migration method
Use of new algorithms of seismic data processing allows to disti nguish pinnacle reefson seismic sections earlier inaccessible for visualizati on because of their shape (small horizontal and great vertical dimensions). High density of the shooting geometry, wide azimuthality of modern seismic survey in the northeast of the Khoreyverskaya depression, and carefully selected processing graph using the latest noise reduction and migration algorithms, provided high‑quality images of such exotic objects as pinnacle reefs. The lateral extension of the buildings indicates that the belt of the pinnacle reefs conti nues beyond the seismic survey area. However, there were seismic data for cross‑border regions from past years with a narrow‑azimuthal, less dense shooting geometry traditional for the region, and processed according to a standard, yearly formed graph. Traps in such reefs are usually characterized by 100 % fill and high density of reserves, therefore they are reputed as interesting oil prospects. Their identification and geometrizati on is possible by attracting results of the duplex wave migration to interpretati on of standard seismic data. Such technique has been used in an area of the Timan‑Pechora OGB, where it permitted not only to delineate an object of the “pinnacle” reef type, but also to map a stretched barrier reef not visible earlier on standard seismic sections, but supposed to exist based on general geological considerati ons.
METHODOLOGY OF PROSPECTING AND EXPLORATION OF OIL AND GAS FIELDS
E.G. Grunis, D.I. Khasanov. Reserves calculation using the volume and probability methods with the aid of Petrel-2013 program package
The article presents volumetric and multivariant methods of reserves calculation developed for calculation of super-viscous oil reserves using "Petrel-2013" program package. The effectiveness and reliability of the interpolation methods provided in "Petrel-2013" program package were investigated in studying bitumen accumulation process in the territory of the Republic of Tatarstan. The results of comparative analysis of these methods and the classical interpolation (averaging) technique used in the volumetric method of reserve calculation is presented. It was concluded that creation of the most accurate three-dimensional model of an uplift with the irregular grid of observation requires a combined use of methods for each data set and selection of the most suitable of them after performance of their cross-validation. When normal distribution in the data set is not observed (and the grid of observation is irregular) the best results of the lithology modelling are achieved by the methods based on indicative kriging. It is shown that calculations of reserves by the probability and volumetric (deterministic) methods based on a geological model produce different results because in volume method all calculated parameters are averaged without spatial distribution of the parameter being processed, while using the multivariant modeling this distribution is accounted for, which is confirmed by higher values of correlation factor obtained for the chosen methods of interpolation of multivariant calculation as compared to the volumetric averaging. Thus, the average value of a parameter estimated by the volumetric method differs from the estimates obtained by the multivariant technique (P90, P50, P10).