scholarly journals Problems of Transporting "Heavy" Gas Condensates at Negative Ambient Temperatures and Ways to Solve These Problems

2021 ◽  
Author(s):  
Hofmann M ◽  
Sudad H Al-Obaidi ◽  
Patkin AA
Keyword(s):  
Gas Condensate ◽  
Pipeline System ◽  
Ambient Temperatures ◽  
The North ◽  
Gas Condensates ◽  
Winter Conditions ◽  
Heavy Gas

The transportation of heavy gas condensate through the pipeline system is conducted in accordance with the approved delivery plan, which provides for the operation of the system in various modes and circumstances. One of the main problems in transporting such gas condensate is the low (negative) ambient temperature.The results of this work are presented, on the basis of which two methods of solving the problem of transporting "heavy" gas condensates in the winter conditions of the North are proposed. The first method involves the use of overpressure, which prevents the formation of structures in gas condensates at sub-zero temperatures; the second method involves the useof a solvent than which it is proposed to use "light" gas condensates.

Methods of Stabilization of Gas Condensates

2018 ◽  
Author(s):  
Ibukun Makinde
Keyword(s):  
Single Phase ◽  
Phase State ◽  
Liquid Mixtures ◽  
Gas Condensate ◽  
Liquid Hydrocarbons ◽  
Light Hydrocarbons ◽  
Natural Gases ◽  
Gas Condensates ◽  
Single Phase State

Gas condensates are liquid mixtures of high-boiling hydrocarbons of various structures, separated from natural gases during their production at gas condensate fields. When transporting gas through pipelines, the following gas quality conditions should be met:i.During transportation, gases should not cause corrosion of pipelines, fittings, instruments, etc.ii.The quality of the gas must ensure its transportation in a single-phase state i.e., liquid hydrocarbons, gas condensates and hydrates should not form in the pipelines.In order for gas condensates to meet the above-mentioned quality conditions during storage or transportation, they must be stabilized. Gas condensate stabilization is the process of “boiling off” light hydrocarbons from the condensate that would otherwise increase the vapor pressure when conditions are fluctuating.

scholarly journals THE TEST RESULTS OF LOW-PERMEABILITY SHALE DEPOSITS WHEN DRILLING THE PRE-CRETACEOUS COMPLEX AT THE KARMALINOVSKOYE GAS CONDENSATE FIELD

2019 ◽  
pp. 45-58
Author(s):  
A. A. Zakharov ◽  
S. V. Korotkov ◽  
A. I. Gritsenko ◽  
R. A. Ivakin ◽  
V. G. Griguletsky
Keyword(s):  
Hydraulic Fracturing ◽  
Flow Rate ◽  
Gas Condensate ◽  
Low Permeability ◽  
Test Results ◽  
North West ◽  
The North ◽  
Exploratory Wells

The article reports the results of the analysis of the field prospecting activities of five exploratory wells at the Karmalinovskoye gas condensate field. We have found that the eastern part of the licensed area is characterized by the lack of fructuring in Paleozoic deposits, and the development of the productive deposit extends in the north-west direction. Hydraulic fracturing made it possible to get a stable gas and gas condensate flow rate in well № 4. This volume exceeds 3,8 times as large than flow rate in wells № 1 and № 2, which were tested after drilling without conducting hydraulic fracturing.

scholarly journals CHROMOSOME STUDIES IN WILD POPULATIONS OF DROSOPHILA MELANOGASTER. II. RELATIONSHIP OF INVERSION FREQUENCIES TO LATITUDE, SEASON, WING-LOADING AND FLIGHT ACTIVITY

Genetics ◽  
1980 ◽  
Vol 95 (1) ◽  
pp. 211-223
Author(s):  
Harrison D Stalker
Keyword(s):  
Drosophila Melanogaster ◽  
Warm Season ◽  
Cold Season ◽  
South Texas ◽  
Temperature Adaptation ◽  
Wing Loading ◽  
Ambient Temperatures ◽  
The North ◽  
Wing Load ◽  
Relationship Of

ABSTRACT In the midwestern and eastern U.S. populations of Drosophila melanogaster, the Standard gene arrangements show higher frequencies in the north than in the south. In a Missouri population, and to a lesser extent in a south Texas population, the frequencies of Standard chromosomes regularly rise during the cold season and drop during the warm season, thus paralleling the north-south frequency differences. In the Missouri population in 1976 and 1978, wild males were tested far their ability to fly to bait at different ambient temperatures. In both years, males flying in nature in the temperature range of 13° to 15° showed significantly higher frequencies of Standard chromosomes than did those flying in the 16° to 28° range. Wild males flying at 13° to 15° also have different tharax/wing proportions and significantly lower wingloading indices than do those flying at 16° to 28°. Moreover, wild flies homozygous Standard in 2R and/or 3R have significantly lower wing-loading indices than flies carrying inversions in these arms. Thus, wild flies with high frequencies of Standard chromosommes are karyotypically northern, are selectively favored during the cold season, have a relatively low wing-load and are most capable of flying at critically low ambient temperatures.—In summary, in Missouri, presence or absence of the common cosmopolitan inversions is an important factor in low temperature adaptation, and at least part of the adaptive mechanism involves control of thorax/wing proportions and thus control of wing-loading.

scholarly journals Sympatric Atlantic puffins and razorbills show contrasting responses to adverse marine conditions during winter foraging within the North Sea

2019 ◽  
Vol 7 (1) ◽  
Author(s):  
Katie St. John Glew ◽  
Sarah Wanless ◽  
Michael P. Harris ◽  
Francis Daunt ◽  
Kjell Einar Erikstad ◽  
...  
Keyword(s):  
North Sea ◽  
Environmental Conditions ◽  
Trophic Position ◽  
Survival Rates ◽  
Sympatric Species ◽  
Ecological Niches ◽  
Overwinter Survival ◽  
The North ◽  
Winter Conditions ◽  
The North Sea

Abstract Background Natural environments are dynamic systems with conditions varying across years. Higher trophic level consumers may respond to changes in the distribution and quality of available prey by moving to locate new resources or by switching diets. In order to persist, sympatric species with similar ecological niches may show contrasting foraging responses to changes in environmental conditions. However, in marine environments this assertion remains largely untested for highly mobile predators outside the breeding season because of the challenges of quantifying foraging location and trophic position under contrasting conditions. Method Differences in overwinter survival rates of two populations of North Sea seabirds (Atlantic puffins (Fratercula arctica) and razorbills (Alca torda)) indicated that environmental conditions differed between 2007/08 (low survival and thus poor conditions) and 2014/15 (higher survival, favourable conditions). We used a combination of bird-borne data loggers and stable isotope analyses to test 1) whether these sympatric species showed consistent responses with respect to foraging location and trophic position to these contrasting winter conditions during periods when body and cheek feathers were being grown (moult) and 2) whether any observed changes in moult locations and diet could be related to the abundance and distribution of potential prey species of differing energetic quality. Results Puffins and razorbills showed divergent foraging responses to contrasting winter conditions. Puffins foraging in the North Sea used broadly similar foraging locations during moult in both winters. However, puffin diet significantly differed, with a lower average trophic position in the winter characterised by lower survival rates. By contrast, razorbills’ trophic position increased in the poor survival winter and the population foraged in more distant southerly waters of the North Sea. Conclusions Populations of North Sea puffins and razorbills showed contrasting foraging responses when environmental conditions, as indicated by overwinter survival differed. Conservation of mobile predators, many of which are in sharp decline, may benefit from dynamic spatial based management approaches focusing on behavioural changes in response to changing environmental conditions, particularly during life history stages associated with increased mortality.

The Strathspey Field, Block 3/4a, UK North Sea

2003 ◽  
Vol 20 (1) ◽  
pp. 355-368
Author(s):  
G. Maxwell ◽  
R. E. Stanley ◽  
D. C. White
Keyword(s):  
North Sea ◽  
Volatile Oil ◽  
Lower Jurassic ◽  
Third Party ◽  
Water Flooding ◽  
Seismic Survey ◽  
Pipeline System ◽  
The North ◽  
Oil Export ◽  
Condensate Reservoir

AbstractThe Strathspey Field was the first sub-sea development in the North Sea to be tied back to a third party operator, the Ninian Field now operated by Canadian Natural Resources (CNR). The field was discovered in 1975 by well 3/4-4 and lies wholly within Block 3/4a. The field is a tilted fault block, unconformity trap and consists of two separate reservoirs, a volatile oil and a gas condensate reservoir: the Middle Jurassic, Brent Group and the Lower Jurassic/Upper Triassic, Banks Group respectively. Two 3D seismic surveys cover the field, the most recent being a Vertical Cable Seismic survey recorded in 1996.The Banks Group reservoir is produced under depletion drive by five wells and the Brent Group reservoir by water flooding with 3 water injectors and 6 producing wells. In place volumes are 290 BCF and 90MMSTB for the Banks Group and 120MMSTR in the Brent Group Reservoir. Ultimate recoveries are estimated to be 230BSCF, 22MMBBL and 70MMSTB, 88 BSCF respectively. Oil export is via the Ninian pipeline system to Sullom Voe, while gas export is through the Far North Liquids and Gas System (FLAGS) pipeline system to St Fergus.]

Application of Tracers in Oil-Based Mud for Obtaining High-Quality Fluid Composition in Lean Gas/Condensate Reservoirs

2007 ◽  
Vol 10 (01) ◽  
pp. 5-11 ◽  
Author(s):  
Fathollah Gozalpour ◽  
Ali Danesh ◽  
Adrian Christopher Todd ◽  
Bahman Tohidi
Keyword(s):  
Drilling Fluid ◽  
Gas Condensate ◽  
Fluid Composition ◽  
Drilling Process ◽  
Two Fluids ◽  
The North ◽  
Reservoir Fluid ◽  
Partially Miscible ◽  
The North Sea ◽  
Mud Filtrate

Summary Oil-based drilling fluids are used extensively in drilling activities worldwide. During the drilling process, because of overbalance pressure in the mud column, the filtrate of oil-based mud invades the formation. This hydrocarbon-based filtrate mixes with the formation hydrocarbon, which can cause major difficulties in obtaining a representative reservoir-fluid sample. Despite the recent improvements in sampling, obtaining a contamination-free formation fluid is a major challenge, particularly in openhole wells. Depending on the type and conditions of the reservoir, the oil-based-mud filtrate is totally or partially miscible with the formation fluid. Oil-based-mud filtrate dissolves completely in reservoir oil; therefore, the captured sample contains the true reservoir oil with added filtrate. Gas condensate (lean gas condensate in particular) is often not fully miscible with mud filtrate. In this case, the mass exchange between gas condensate and mud filtrate makes the sample unrepresentative of the reservoir fluid. In this study, the impact of sample contamination with oil-based-mud filtrate on different types of reservoir fluids, including gas condensate and volatile-oil samples, is investigated. Two simple methods are suggested to retrieve the uncontaminated composition from a contaminated sample in which mud filtrate is totally dissolved in the formation fluid (i.e., reservoir-oil samples). A tracer-based technique is also developed to determine the composition of an uncontaminated reservoir-fluid sample from a sample contaminated with oil-based-mud filtrate, particularly for those cases in which the two fluids are partially miscible. The tracers are added to the drilling fluid, with the additional cost to the drilling-mud preparation being negligible. The capability of the developed techniques has been examined against deliberately contaminated reservoir-fluid samples under controlled conditions in the laboratory. The results indicate the reliability of the proposed methods. Introduction Historically, most drilling in the North Sea has used water-based muds; however, drilling certain formations with water-based muds can be difficult, primarily because of the hole instability caused by the swelling of water-absorbing rock. Problems of this type can be greatly alleviated by using mud suspended in an oil (rather than water) base. These oil-based muds also provide better lubrication and achieve significant increases in drilling progress (Davies et al. 1984). In recent years, oil-based drilling fluid has been used extensively in drilling activities in the North Sea. During the drilling process, because of overbalance pressure in the mud column, the mud filtrate invades the reservoir formation. Using an oil-based mud in the drilling, the mud filtrate can mix with the formation fluid. This can cause major difficulties in obtaining high-quality formation-fluid samples. Depending on the type and conditions of the reservoir, the mud filtrate can be totally or partially miscible with the formation fluid. This can alter the composition and phase behavior of the reservoir fluid significantly. Hence, the measured data using the collected formation-fluid samples need to be corrected for the contamination. In this study, contamination of different types of reservoir fluids with oil-based-mud filtrate, where the two fluids are partially or totally miscible, is discussed. Practical decontamination techniques are proposed to retrieve the original fluid composition from contaminated samples.

Security for Pipeline Assets: The State of the Art

2002 ◽  
Author(s):  
Moness Rizkalla ◽  
Jeff Brown
Keyword(s):  
Pipeline System ◽  
Law Enforcement Agencies ◽  
Holistic View ◽  
Sustainable Solutions ◽  
Customized Training ◽  
Technological Adaptation ◽  
The North ◽  
Security Challenge ◽  
Rapid Restoration ◽  
Enforcement Authority

The North American energy pipeline system represents a security challenge. Taking a holistic view of the problem allows the operator to construct and implement a strategy systematically. The solution involves a multi-disciplinary approach using a combination of business tools and technology to provide enhanced protection, and rapid restoration and recovery in the event of an attack. • Mapping of “high consequence” areas, including pipeline segments near population centers, water resources, or environmentally sensitive regions, will allow energy companies to more logically allocate security resources, but there may remain vast stretches of pipeline where physical barriers are impractical. • Formal decision analysis techniques can be effectively used to assess potential threats, analyze vulnerabilities, prepare contingency plans and set priorities. • Hardware elements of the solution will draw heavily upon technological innovations, including the use of active earth observation imagery and sophisticated sensing equipment for surveillance and early detection. • Strategic planning exercises will allow operators to think through the problem before a threat occurs and to put in place resources to react to a threat and to respond, restore, and recover from an attack. This is particularly true in coordination across a region. The expanding effort to safeguard the continent’s energy infrastructure will rely upon a greater level of (1) government-industry cooperation, particularly in the areas of data and information collection/analysis/dissemination, (2) technological adaptation/innovation, including greater use of sensing and surveillance technologies, (3) the development of financial and insurance products that fit the specific needs of energy asset owners and operators, (4) communication with key constituencies: customers, suppliers, regulators, law enforcement agencies, and financial markets, (5) customized training for employees, (6) government supervisory and enforcement authority to inspect and penalize companies that do not implement the appropriate level of security, while providing a due diligence safe harbor for those that are proactive; and (7) an unwavering commitment to protect vital assets, human, physical, and otherwise. It is critical that pipeline security programs focus on long-term, sustainable solutions that are customized to fit the specific needs of particular energy asset networks. The paper contains a specific example of pipeline infrastructure management system and display screen examples.

Fundamental PVT Calculations for Associated and Gas/Condensate Natural-Gas Systems

2007 ◽  
Vol 10 (03) ◽  
pp. 270-284 ◽  
Author(s):  
Robert P. Sutton
Keyword(s):  
Compressibility Factor ◽  
Pure Component ◽  
Gas Condensate ◽  
High Gravity ◽  
Pvt Properties ◽  
Reduced Pressure ◽  
Data Set ◽  
Associated Gas ◽  
Gas Condensates ◽  
Compressibility Factors

Summary Problems with existing procedures used to estimate gas pressure/volume/temperature (PVT) properties are identified. The situation is reviewed, and methods are proposed to alleviate these problems. Natural gases are derived from two basic sources: associated gas, which is liberated from oil, and gas condensates, where hydrocarbon liquid, if present, is vaporized in the gas phase. The two gases are fundamentally different in that a high-gravity associated gas is typically rich in ethane through pentane, while gas condensates are rich in heptanes-plus. Additionally, either type of gas may contain nonhydrocarbon impurities such as hydrogen sulfide, carbon dioxide, and nitrogen. Failure to distinguish properly between the two types of gases can result in calculation errors in excess of those allowable for technical work. Sutton (1985) investigated high-gravity gas/condensate gases and developed methods for estimating pseudocritical properties that resulted in more-accurate Z factors. The method is suitable for all light natural gases and the heavier gas/condensate gases. It should not be used for high-gravity hydrocarbon gases that do not contain a significant heptanes-plus component. The original Sutton database of gas/condensate PVT properties has been expanded to 2,264 gas compositions with more than 10,000 gas-compressibility-factor measurements. A database of associated-gas compositions containing more than 3,200 compositions has been created to evaluate suitable methods for estimating PVT properties for this category of gas. Pure-component data for methane (CH4), methane-propane, methane-n-butane, methane-n-decane, and methane-propane-n-decane have been compiled to determine the suitability of the derived methods. The Wichert (1970) database of sour-gas-compressibility factors has been supplemented with additional field and pure-component data to investigate suitable adjustments to pseudocritical properties that ensure accurate estimates of compressibility factors. Mathematical representations of compressibility-factor charts commonly used by the engineering community and methods used by the geophysics community are investigated. Generally, these representations/methods are robust and have been found suitable for ranges beyond those recommended originally. Natural-gas viscosity, typically estimated through correlation, has been found to be inadequate for high-gravity gas condensates, requiring revised procedures for accurate calculations. Introduction Since its publication, the Standing and Katz (1942) (SK) gas Z-factor chart has become a standard in the industry. Several very accurate methods have been developed to represent the chart digitally. The engineering community typically uses methods published by Hall and Yarborough (1973, 1974) (HY), Dranchuk et al. (1974) (DPR), and Dranchuk and Abou-Kassem (1975) (DAK). These methods all use some form of an equation of state that has been fitted specifically to selected digital Z-factor-chart data published by Poettmann and Carpenter (1952). The geophysics community typically uses a method developed by Batzle and Wang (1992) (BW). Recently, Londono et al. (2002) (LAB) refitted the chart with an expanded data set, resulting in a modified DAK method. They provided two equations: one fit to an expanded data set from the SK Z-factor chart and another that included pure-component data. A general gas Z-factor chart, such as the one developed by Standing and Katz (1942), is based on the principle of corresponding states (Katz et al. 1959). This principle states that two substances at the same conditions referenced to critical pressure and critical temperature will have similar properties. These conditions are referred to as reduced pressure and reduced temperature. Therefore, if two substances are compared at the same reduced conditions, the substances will have similar properties. In the context of this paper, the property of interest is the gas Z factor. Mathematically, the SK chart relates Z factor to reduced pressure and reduced temperature.

scholarly journals Tintinnid Ciliate Communities in Pre- and Post-Winter Conditions in the Southern Adriatic Sea (NE Mediterranean)

Water ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 2329 ◽  
Author(s):  
Jakica Njire ◽  
Mirna Batistić ◽  
Vedrana Kovačević ◽  
Rade Garić ◽  
Manuel Bensi
Keyword(s):  
Adriatic Sea ◽  
Sea Water ◽  
Dynamic Environment ◽  
Intermediate Water ◽  
The North ◽  
Winter Conditions ◽  
Winter Convection ◽  
Oceanic Species ◽  
Physical Forces ◽  
The Impact

The Southern Adriatic Sea is a dynamic region under the influence of diverse physical forces that modify sea water properties as well as plankton dynamics, abundance, and distribution in an intricate way. The most pronounced being: winter vertical convection, lateral exchanges between coastal and open sea waters, and the ingression of water masses of different properties into the Adriatic. We investigated the distribution and abundance of tintinnid species in this dynamic environment in pre- and post-winter conditions in 2015/2016. A strong ingression of the saline Levantine Intermediate Water, supported by the cyclonic mode of the North Ionian Gyre in 2015 and 2016, in December was associated with a high diversity of oceanic species. An unusual spatial distribution of neritic-estuarine species Codonellopsis schabi was observed in deeper layers along the analyzed transect, which emphasizes the strong influence of physical processes on deep water biology in the South Adriatic. A shift of population toward greater depths (mesopelagic) and modification of deep sea community structure was recorded in April as a consequence of the winter convection-driven sinking of tintinnids. Our findings indicate that tintinnid abundance and composition is heavily influenced by physical conditions and they are good indicators of the impact of physical forces, including climate changes, on marine environment.

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