Urengoy Field Research Articles

Carbon dioxide injection into the Achimov formations using reinjection technology by the example of Ach3-4 formation in the Novo-Urengoy area of the Urengoy field

The prerequisites for the study are the calculation results for the cycling process, where carbon dioxide is proposed as the injection agent into the Achimov formations instead of dry gas, with the goal of increasing the condensate recovery factor. The work is focused on the efficiency assessment of carbon dioxide reinjection technology and reducing carbon footprint at a late stage of field development. The research object is the Аch3-4 formation within the Novo-Urengoy license area of the Urengoy field. The leading method to identify this problem is the results of the full-scale composite dynamic model in the ECLIPSE 300 format. The model takes into account the history of field development on depletion. The articles deals with two schemes for injecting carbon dioxide into the formation. In the first scheme, pure carbon dioxide is injected in a closed-loop system, but carbon neutrality through storage is not achieved. In the second scheme, carbon dioxide is injected using reinjection technology. Once injection begins, gas production stops. Only the condensate separated from the formation gas during low-temperature separation is sold and sent for further processing. After allocation of the condensate, the mixture of natural gas and carbon dioxide, in a specific proportion, is sent to the compressor station for reinjection into the formation in a gaseous state. Injecting pure carbon dioxide achieves a condensate recovery factor similar to that of gas injection with a 30 % carbon dioxide mixture. However, this option is less economically viable compared to the base and other scenarios due to high capital costs for upgrading the existing gas processing equipment (requiring the construction of an amine treatment unit). With carbon dioxide injection using reinjection technology, in addition to recovering extra condensate that had condensed during natural depletion, a reduction in the carbon footprint is also achieved. To maximize the condensate recovery factor, the optimal concentration of carbon dioxide in the injection mixture has been determined. The optimal timing for the start of injection was identified to maximize gas recovery. Economic efficiency is expected from the additional recovery of condensate trapped in the reservoir and from achieving carbon neutrality through the monetization and storage of carbon dioxide.

SATELLITE DATA IN THE STUDY OF THE ARCTIC LANDSCAPES THAWING UNDER THE CONDITIONS OF OIL AND GAS PRODUCTION

The issues of climate warming and permafrost thawing are considered. A procedure for assessing the Arctic landscapes thawing based on the calculation of the normalized differential snow index (NDSI) is proposed. The factual material over the data of the global permafrost monitoring network is presented. Monitoring studies have shown that according to the results of NDSI calculation, abnormally early snowmelt was detected in 5 cases out of 23 years of observation at the Urengoy meteorological station and in 4 cases out of 23 years at the Tarko-Sale meteorological station. The absence of snow was observed during the indicated period in 13 cases at the technogenic sites of the Urengoy field, and in 8 cases at the Tarko-Sale field. With early snowmelt, the snow index NDSI decreases, and the depth of the seasonally thawed layer increases at the sites of the Urengoy field. The NDSI index can be used directly in assessing the duration of snow cover and early snowmelt, and indirectly in studying the depth of seasonally thawed layer. The results obtained are important for predictive estimates of the rate and extent of thawing and permafrost deformation, and for the prevention of emergency situations in the oil and gas complex.

Filtration studies on cores and sand packed tubes from the Urengoy field for determining the efficiency of simultaneous water and gas injection on formation when extracting condensate from low-pressure reservoirs and oil from oil rims

Oil rims as well as gas condensate reservoirs of Russia's largest Urengoy field are developed by depletion drive without formation pressure maintenance, which has led to serious complications in production of oil, gas and condensate. In addition, field development by depletion drive results in low values of oil and condensate recovery. These problems are also relevant for other oil and gas condensate fields. One of the possible solutions is simultaneous water and gas injection. Rational values of gas content in the mixture for affecting gas condensate fields and oil rims of oil and gas condensate fields should be selected using the data of filtration studies on core models. The article presents the results of filtration experiments on displacement of condensate and oil by water, gas and water-gas mixtures when simulating the conditions of the Urengoy field. Simultaneous water and gas injection showed good results in the experiments on displacement of condensate, residual gas and oil. It has been ascertained that water-gas mixtures with low gas content (10-20 %) have a better oil-displacement ability (9.5-13.5 % higher) than water. An experiment using a composite linear reservoir model from cemented core material, as regards the main characteristics of oil displacement, gave the same results as filtration experiments with sand packed tubes and demonstrated a high efficiency of simultaneous water and gas injection as a method of increasing oil recovery at oil and gas condensate fields.

Пространственное распределение естественного и антропогенного эолового рельефа на севере Западной Сибири

The authors show the differentiation of the modern aeolian landforms spatial distribution (natural and anthropogenic origin) for the northern part of the West Siberian Plain (an area of about 800 thousand km2) based on the analytical processing of Sentinel-2 satellite images (resolution 10 m/px). A deciphering technique was developed; it includes the use of unsupervised ISODATA classification algorithms, visual editing, verification of results based on high-resolution satellite images, and standard spatial analysis procedures. In total, 404,675 aeolian relief objects with a total area of 2228,18 km2 were identified. The average area of natural forms was 0,44 ha (the largest share in the Yamal district of the Yamalo-Nenets Autonomous Okrug – 1,02 %), the average area of anthropogenic forms – 2,84 ha (the largest share in the Purovsky district of the same region – 0,19 %). It was revealed that in the territories of oil and gas production, the maximum area of both natural and anthropogenic aeolian forms corresponds to the boundaries of the Urengoy field (19,14 and 34,58 km2, respectively). It was established that in the Yamal Peninsula, the modern aeolian relief is confined mainly to marine and hydroglacial deposits, while in that of Gydan Peninsula, a connection can be traced with glacial or marine ones that have experienced direct mechanical action of cover ice. It was revealed that the mentioned relief is often formed in areas with increased drainage, facing towards the direction of the prevailing winds in the spring-autumn period (terraces and the watershed of the Pur and Nadym rivers). The results of the study can be used at monitoring the reclamation of disturbed areas and the natural dynamics of vegetation as an indicator of global climate change in the north of Western Siberia.

Efficiency of the peripheral and combined gas-distribution in torches of coppers of the TGM-84

So far rather large number of torches for chamber combustion of gaseous fuel differing among themselves on the nature of gas-distribution for mixture of fuel with air is known. For domestic oil-gas torches of power coppers their unification as combustion of fuels is characteristic, that is heat of combustion of the burned fuel can change in quite wide limits. Moreover, directly in use on thermal power plant their reconstruction is made for reduction of length of a torch, achievement of uniform radiation of a torch, change of local values of temperatures of a torch or reduction of their maximum values. As a rule, the detailed researches received after reconstruction of these torches are not conducted. Foreign torches are designed and made on combustion of fuel of a concrete type with the set heat of combustion. At the same time the main role for increase in efficiency is assigned to computer regulation of a ratio of fuel and air, gas-distribution - central tubular. Except high cost, the difficulty of application of foreign torches for domestic power coppers is connected with adaptation of automatic equipment of these torches to the system of automation of domestic coppers. Therefore for domestic coppers one of the directions them modernization for the purpose of increase in efficiency is reconstruction of schemes of gas-distribution in the existing torches. In this article the efficiency of application of peripheral tubular gas-distribution in comparison with the combined peripheral tubular gas-distribution combined with conic central gas-distribution when using as the main tagentsialny peripheral twist of air is investigated. These schemes of gas-distribution are applied in coppers of TGM-84A of the Kazan TES-3 and the Nizhnekamsk TES-1 on which experiments on identification of efficiency of these types of gas-distribution for combustion of natural gas of the Urengoy field are made.

Технологии эксплуатации самозадавливающихся скважин Уренгойского месторождения

Технологии эксплуатации самозадавливающихся скважин Уренгойского месторождения

Режимы проведения исследований с применением технологий фильтрации на газоконденсатных месторождениях

The article shows the methods of hydrodynamic research: in stationary and non-stationary mode, which were carried out at the Urengoy gas condensate field. The filtration resistance coefficients A (by the nature of opening a gas well) and B (by the degree of opening of a gas well) are determined in the article. As a result, conclusions were drawn that in the process of developing the Urengoy field in recent years, the coefficients A and B did not change significantly. As a result of the analysis of hydrodynamic studies at the Urengoyskoye field, several recommendations have been made to improve the development of the Senoman reservoir. The most important is the conduct of PIP to assess the adhesion of cement stone to the column and filling the annular space with cement mortar in the intervals of opening of productive thicknesses, this is indicated by the anomalies of the internal pressure coefficient.

Transformation of deep fluid flow in the process of oil and gas field formation of north Western Siberia

Since the discovery of giant hydrocarbon fields in the north of Western Siberia, no unified concept regarding the mechanism and stages of their formation has been developed. This paper on the example of the Urengoy field demonstrates that the formation of HC accumulations from Jurassic to Cenomanian is related to hydrocarbon fluids, flowing upwards from the deep depth, and their subsequent transformation. In the sedimentation process, the gases of the secondary kerogen destruction form an upward fluid flow, which dissolves oil components from source rocks and carry them to shallower depths. The formation waters of the north Western Siberia are methane-saturated; so, due to changes in its solubility during the Neogene uplift, methane comes out into a free phase. The calculations were performed on the upward flow phase separation and oil and gas content changes in reservoirs with depth. The addition of 50 mole% of methane released from the water to the Neocomian reservoirs gives a good agreement on the C1-C4 components and the C5+ content in the formation gas. The calculations were based on the proposition that methane captures light fractions from oil rims, thus increasing oil density. At shallow depths, the hydrocarbons are biodegraded, which leads to formation of almost pure methane accumulations in the Cenomanian reservoirs. The main mechanism of the upward flow transformations, controlling the oil and gas accumulation, is phase transitions. The additional factors, like methane dissolution in water and its transition into a free phase, microbial converting of hydrocarbons assure consistency between the calculated formation fluid properties and the actual data in the entire sedimentary section.

RESULTS OF INFLOW INTENSIFICATION AT THE URENGOY FIELD

Background The article discusses the results of the intensification of the inflow at Urengoy oil and gas condensate field. It is shown that the most successful method of inflow intensification is hydraulic fracturing. During the further exploitation of the field, the hydraulic fracturing will be the main effective method of intensifying the gas condensate wells inflow. Aims and Objectives To assess the methods of inflow intensification used at Urengoy oil and gas condensate field. Results The analysis of the applied methods of inflow intensification at Urengoy field has been performed. The most frequently used methods of stimulation of inflow are considered. It was established that the main effective method of intensifying inflow of gas condensate wells at Urengoy field in the near future (within 2-3 years) will be hydraulic fracturing, including through delayed development technology use. Nevertheless, it is necessary to note that the situation largely depends on the effectiveness of the geophysical and hydrochemical control system and qualified geological and technical solutions.

TO THE QUESTION OF LOW-TEMPERATURE SEPARATION TECHNOLOGY EFFICIENCY

Currently, natural gas is widely used in the energy and chemical indus- tries. It is as an inexpensive high efficiency fuel. For gas transportation pipeline transport is mainly used, which has high productivity and efficiency. However, in the process of transportation there are various complications. They are: corrosion of the pipeline and equipment, formation and deposition of hydrocarbon liquid, water con- densate and gas hydrates. In order to avoid these problems, it is necessary to carry out field treatment of the extracted raw materials. Gas and gas condensate fields are specified by high pressures within the reservoir at early stages of development. In the process of extraction, gas leaves the well with a significant pressure, of 10-15 MPa and higher. With this feature, it is advisable to treat the gas by low-temperature separation method. By throttling the flow, it is possible to obtain cold practically free due to the energy contained in the high-pressure gas streams themselves. This method is widely used and it requires a minimum of capital invest- ment. Simple service and maintenance of the equipment is also a positive factor. This article considers one of the possible options for gas and gas conden- sate treatment plans, namely the three-stage low-temperature separation used in the gas condensate field of the Urengoy field. For this technologi- cal chain, the main stages of raw materials treatment are considered and the designs of the equipment used are described. In order to evaluate the efficiency of the method and the quality of the products being treated, the results of the gas sample and gas condensate tests are presented, followed by a comparison of the required criteria (characteristic and composition of commercial gas and unstable gas condensate, dew-point temperature, heavy hydrocarbon droplet entrainment) with acceptable values. These data show that with the use of low-temperature separation technology, it is possible to achieve the required quality standards of the products being treated, but thanks to the use of energy from gas streams, the process of purification of petroleum raw materials occurs at a much lower cost.

CONCERNING TO REMOVAL METHODS HYDRATE FORMATION (ON EXAMPLE OF URENGOY FIELD)

Background At present, the development of gas fields is in most cases complicated by the increase in moisture content in natural gas. The main reason for this phenomenon is a decrease in pressure, gas temperature and, as a result, this leads to the appearance of water vapor that has condensed and accumulated in wells and gas pipelines. Further saturation of natural gas at an elevated pressure and positive temperature can lead to the formation of solid physicochemical compounds - hydrates. The occurrence of such crystalline substances can lead to the blockage of wells, gas pipelines, separators, disruption of the work of stabilizing and gauging devices, and as a result to a decrease in the level of oil production. Often, pressure regulators and fittings fail, gas is throttled, accompanied by a sharp decrease in temperature, and the disruption of the normal operation of the oil and gas production equipment. Aims and Objectives Determination of factors affecting the intensity of hydrate formation, and the study of methods to combat the formation of gas hydrates on the example of the Urengoy field. Results The factors that directly affect the intensity of hydrate formation are determined: moisture content, temperature, pressure, component composition of the gas. The possible places for gas hydrates formation are given: at fittings, in piping of pipes, in separators, in loops, on diafragms of metering sections. The main methods of preventing the hydrate formation and removal of hydrate plugs are present: increasing the gas temperature, reducing the gas pressure, removing moisture from the gas using absorbents and adsorbents, inhibitors. Methods for the control of hydrate formation, using in Urengoi field, are presented. A thermal calculation of the plume was performed, which allows determining the temperature change along the gas pipelines and determining the possible place of hydrate formation.

Типизация конусов выноса в ачимовских отложениях Уренгойского месторождения

Типизация конусов выноса в ачимовских отложениях Уренгойского месторождения

Разработка энергоэффективных технических решений по эксплуатации дожимных компрессорных станций Уренгойского месторождения

Разработка энергоэффективных технических решений по эксплуатации дожимных компрессорных станций Уренгойского месторождения

Condensation Mechanism of Hydrocarbon Field Formation

Petroleum geology explains how hydrocarbon fluids are generated, but there is a lack of understanding regarding how oil is expelled from source rocks and migrates to a reservoir. To clarify the process, the multi-layer Urengoy field in Western Siberia was investigated. Based on this example, we have identified an alternative mechanism of hydrocarbon field formation, in which oil and gas accumulations result from the phase separation of an upward hydrocarbon flow. There is evidence that the flow is generated by the gases released by secondary kerogen destruction. This study demonstrates that oil components are carried by the gas flow and that when the flow reaches a low-pressure zone, it condenses into a liquid with real oil properties. The transportation of oil components in the gas flow provides a natural explanation for the unresolved issues of petroleum geology concerning the migration process. The condensation mechanism can be considered as the main process of oil field formation.

Влияние ингибирующих присадок на состав парафиновых отложений газоконденсата Уренгойского месторождения

Влияние ингибирующих присадок на состав парафиновых отложений газоконденсата Уренгойского месторождения

Uplift-related hydrocarbon accumulations: the release of natural gas from groundwater

Abstract Vertical tectonic movements often change the structural style and physicochemical habitat of sedimentary basins. Changes in pressure, temperature and salinity of the groundwater caused by tectonic uplift may result in the release of previously dissolved gas. This process of gas exsolution from groundwater is shown to be an important mechanism in the formation of gas accumulations in uplifted basins. Two principal types of gas release are discussed. A hydrodynamic type is active when groundwater flows into areas of lower pressure or mixes with water of different temperature or salinity. It is anticipated that this effect is more of local importance, but over long periods of groundwater flow large volumes of gas may be exsolved. The hydrostatic type of gas release can occur in any sequence of sedimentary rocks where uplift causes a drop in pressure and temperature. This phenomenon may act basin-wide. Mass balance calculations show that the largest gas accumulations on Earth, such as the Urengoy field in West Siberia, could have been formed by this process.

Gas Generation and Accumulation in the West Siberian Basin

We appreciate the discussion by Murris (2001) and take the opportunity to clarify some of his objections and discuss some of the still open questions in more detail. Murris's main objections to the conclusions of Littke et al. (1999) concern, first, the influence of overpressure in the Lower Cretaceous and Upper Jurassic on hydrocarbon distribution and, second, the model of gas release by exsolution (degassing) from deep ground water as the main mechanism for accumulating the huge gas fields of northern West Siberia. The first objective of Murris's discussion is how the overpressure in Jurassic strata might have influenced the distribution of hydrocarbons in the overlying Cretaceous sediments. Two crucial points regarding this question are the reason and timing of overpressuring and its influence on hydrocarbon movement. We agree with Murris that the effect of compaction disequilibrium is not sufficient to explain the extent of overpressure in the Urengoy area and that hydrocarbon generation in the Bazhenov Formation has contributed to the buildup of overpressure. Two-dimensional basin modeling along a seismic line through the Urengoy field, however, showed that hydrocarbon generation in Jurassic source rocks (Bazhenov and the Tyumen formations) did only generate sufficient overpressure to explain the recent situation if the models were laterally completely sealed. This sealing appears to be highly unlikely. Furthermore, hydrocarbon generation ceased during the Miocene, when the tectonic movement started to lift the source rocks into shallower depths, where lower temperatures were reached. Thus, any overpressure caused by petroleum generation must have been preserved over a period of about 5-20 m.y. In addition, the overpressure is not restricted to the Jurassic Bazhenov Formation but extends into the Cretaceous, including the Achimov sands. Uplift might have contributed to the overpressure, however. Maximum pore pressure from the stage of deepest burial might have …

Thermal and Maturation Modeling of the Urengoy Field, West Siberian Basin: Some Special Considerations in Basin Modeling1

Present-day temperature and vitrinite reflectance (Ro) profiles are considered key factors for calibration in numerical basin modeling; therefore, it is important to understand how such profiles are generated. Basin modeling typically considers factors such as rock consolidation, depth-variation of petrophysical characteristics, changes in heat flow, and paleoclimate; however, our basin evaluations have shown that other processes that influence temperature and Ro (vitrinite reflectance) profiles commonly are inadequately studied. Modeling within the Urengoy field of the West Siberian basin has allowed numerical estimates of some of these nonstandard processes. First, a substantial increase in temperature (up to 5-10iC) is expected from changes in heat conductivity due to the formation of significant free gas, gas-condensate, and condensate. Second, climate variations creating numerous periods of formation and degradation of permafrost zones for the last 3.4 m.y. could decrease the modern rock temperatures by 10-17iC in the upper 1.5 km of the sedimentary section and up to 10iC at its base. Due to the short duration of these two processes, their effect on organic matter maturation is minimal; nevertheless, their roles in the formation of present-day temperature profiles necessitate their inclusion in basin modeling. Third, modeling results demonstrated that change in heat conductivity of rocks with dispersed organic matter can increase temperature of sedimentary rocks by 3-5iC and rock maturity by not more than 0.02% (Ro). Finally, the sharp increase in vitrinite reflectance (% Ro) with depth, typical for the deep sedimentary units of the Urengoy field and many other continental rift basins, is possible to explain from hydrothermal activity. The influence of these processes on subsurface temperatures and maturation of organic matter can vary significantly depending on lithology, organic matter content, and the location of the modeled section relative to the ancient rift system. The results of this study can help one estimate the relative influence of these parameters.

Numerical simulation of permafrost evolution as a part of sedimentary basin modeling: permafrost in the Pliocene–Holocene climate history of the Urengoy field in the West Siberian basin

Present-day temperature profile may be used as an important constraint for reconstruction of the thermal regime in sedimentary basin modeling. This type of profile is significantly non-steady state, especially for basins located at high and middle latitudes. However, estimations of past thermal regimes are indefinite and often limited by knowledge of past glaciations and by the simple two-layer model usually employed. In this paper, permafrost modeling was carried out as a continuation of basin modeling of the sedimentary section of Urengoy field of the West Siberian basin (66°N, 77°E). Consideration of surface temperatures beginning with the Triassic, a refined initial temperature distribution, permafrost modeling for the past 3.4 Ma, and use of a real lithological cross section distinguish this approach from previous studies. Depth and time variations in thermophysical parameters of rocks (heat conductivity, heat capacity, unfrozen water content, salt content, and porosity) had a considerable influence on the results of modeling. The time 3.4 Ma, when air temperatures in the area became lower than 0 °C, has been considered as the initial time for permafrost modeling. According to the model, initial temperatures deviated 10–15 °C from their present-day values due to climate variations during the last 3.4 Ma. Deviations in the value of heat flow can exceed 100%. There were about five glacial periods in the Late Pliocene and nearly the same number in the Pleistocene in the area. The estimated thickness of permafrost did not exceed 650 m and the depth of the lower boundary of methane hydrate stability did not exceed 900 m (from the ground surface). Today, the predicted depths of permafrost [Formula: see text] and of hydrate stability (from 250 to 700 m) are in reasonable agreement with the observed values for the Urengoy area.

Separate Prognosis and Formation of Hydrocarbon Systems in West Siberia

The west Siberian oil and gas province occupies an area of more than 2.5 million km[sup 2]. More than 1900 oil and gas pools have been discovered there. A study of the vertical and regional distribution of hydrocarbons suggests there is a regular zonation of the various phase state. Within the Mesozoic to Cenozoic series, five major zones have been identified. The first zone of Aptian, Albian, and Cenomanian rocks contains all principal gas accumulations of the province (95% of west Siberian gas) and a number of super giant and giant dry-gas fields have been discovered. Reservoir temperature varies from 9 to 20[degrees]C. The second zone includes Valanginian through lower Aptian rocks and contains gas and oil-gas condensate pools. A group of wet-gas fields is located between the Nadym and Taz rivers, and also on the Yamal and Gydan peninsulas. The total thickness of the Neocomian is 1000 m. Reservoir temperature varies from 30 to 75[degrees]C. The third zone contains mainly oil pools. The zone embraces Valanginian-Hauterivian and Berriasian-Valanginian productive horizons of the middle Ob region. Reservoir temperature is between 70 and 100[degrees]C. The fourth zone comprises Middle and Upper Jurassic rocks and contains oil and gas condensate pools, oilmore » with associated gas-bearing Upper and Middle Jurassic sandstones in the Salym and Krasnolensk region. The oil is lower density than the Neocomian oil and production is smaller. Reservoir temperature reaches 120 to 140[degrees]C. The fifth zone is in the deeply buried rocks of the Achimov Formation and Lower-Middle Jurassic strata of the Urengoy field in the northern part of the basin. The zone contains gas condensate and the reservoir temperature is more than 140[degrees]C. Specific features of the West Siberian basin is the genetic character of the vertical and areal zonation; the distribution and type of hydrocarbons is a function of primary kerogen type and in situ generation and entrapment.« less