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Record W1974414159 · doi:10.2118/67322-ms

Problems in Hydrates: Mechanisms and Elimination Methods

2001· article· en· W1974414159 on OpenAlex

Why this work is in the frame

A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.

affAt least one author lists a Canadian institution in the pinned OpenAlex snapshot.

Bibliographic record

VenueAll Days · 2001
Typearticle
Languageen
FieldEnvironmental Science
TopicMethane Hydrates and Related Phenomena
Canadian institutionsMartec (Canada)Dalhousie University
Fundersnot available
KeywordsClathrate hydrateNatural gasPetroleum engineeringFlow assuranceSubseaHydratePipeline transportSubmarine pipelineEnvironmental scienceFossil fuelPetroleum industryDew pointWaste managementChemistryEnvironmental engineeringGeologyEngineeringThermodynamicsMarine engineering

Abstract

fetched live from OpenAlex

Abstract Unrestricted fluid flow of oil and gas streams is crucial to the petroleum industry. Unless preventative action is taken, gas hydrate plugs form under the high pressure, low temperature conditions inherent to offshore production. The oil and gas industry is facing increasing costs in inhibiting gas hydrate formation due to the development of offshore gas reservoirs. Recent international estimates of the cost of the conventional inhibitor, methanol, alone are in excess of $150 million/year. Gas hydrates are likely to form in subsea flowlines unless the water is removed down to the lowest dew point encountered, highly effective insulation is in place, or inhibitors are used. Since complete stripping of water from condensates and/or natural gas is prohibitively expensive, and effective insulation is beyond current economic limits, the most effective solution includes the use of hydrate inhibitors. This paper describes the state of the art of hydrate prevention, detailing hydrate structure, conditions and mechanisms of formation, and developing approaches - from the conventional to the cutting-edge - to hydrate inhibition. Its focus on low-dosage inhibitors, including a review of kinetic inhibitors and anti-agglomerants form, function, development, selection, modeling and applications, highlights gaps in current knowledge. Finally, a research agenda addressing both mitigation and deployment strategies is proposed. Introduction Since the 1930's when Hammerschmidt1 determined that the material plugging pipelines was gas hydrates, interest in gas hydrates has continued to increase. Hammerschmidt's discovery led to the regulation of the water content in natural gas pipelines2. In 1934, Hammerschmidt published a correlation summary of over one hundred hydrate formation data points. Unrestricted and problem-free flow of petroleum products during extraction, processing, and transportation is essential to the oil and gas industry. Whether heavy hydrocarbons such as crude oil, or low molecular weight hydrocarbons such as natural gas and natural gas liquids are the target end product, natural gas is almost always present in the fluid extracted during production. To varying degrees (most often low early in the life of a reservoir and high toward the end), the extracted oil and gas mixture also contains water. In the presence of water, and under a fixed range of pressure and temperature conditions, specific to each hydrocarbon mixture, hydrates of the light gases can form. Gas hydrates, which have a crystalline structure analogous to that of ice, form solid plugs and block the flow. Clearly, inhibition of hydrate formation is of utmost interest to industry. Hydrate formation is a substantial problem in deepwater production and underwater pipelines, which transport condensed phase hydrocarbons such as gas condensate or crude oil. In these situations, once plugs have formed, there are limited possibilities for removal2. Since the 1970's, the oil and gas industry has faced increasing costs associated with inhibition of gas hydrate formation, due to the development of offshore gas reservoirs. Recent international estimates of the cost of the conventional inhibitor, methanol, alone, are in excess of $150 million/year3. Gas hydrates are likely to form in subsea flowlines unless the water is removed down to the lowest dew point encountered, highly effective insulation is in place, or inhibitors are used. The first option is difficult when supersaturated condensates exist in the flowline even after the gas phase is stripped to saturation levels. Stripping condensate completely of water is prohibitively expensive and effective insulation is beyond current economic limits. Therefore, the most effective solution appears to be the use of inhibitors. Generically, there are two kinds of hydrate inhibitors: thermodynamic inhibitors, and the more recently identified low-dosage inhibitors. Thermodynamic inhibitors have been in use for a long time, and continue to be the industry standard. This kind of inhibitor works as an antifreeze by involving the water in a thermodynamically favourable relationship, so that it is not available for reaction with the gas.

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.

Full frame distilled prediction

Teacher imitation

Not calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.

metaresearch head score (Codex)0.001
metaresearch head score (Gemma)0.000
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesInsufficient payload (model declined to judge)
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Bench or experimental · Consensus signal: none
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.597
Threshold uncertainty score1.000

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0010.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0000.000
Science and technology studies0.0000.000
Scholarly communication0.0000.000
Open science0.0000.000
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0010.000

Machine scores (provisional)

The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.

Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.

Opus teacher head0.020
GPT teacher head0.276
Teacher spread0.256 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it