Establishing Inflow Performance Relationship (IPR) for Gas Condensate Wells
Bibliographic record
Abstract
Establishing Inflow Performance Relationship (IPR) for Gas Condensate Wells Sarfraz A. Jokhio; Sarfraz A. Jokhio University of Oklahoma Search for other works by this author on: This Site Google Scholar Djebbar Tiab Djebbar Tiab University of Oklahoma Search for other works by this author on: This Site Google Scholar Paper presented at the SPE Gas Technology Symposium, Calgary, Alberta, Canada, April 2002. Paper Number: SPE-75503-MS https://doi.org/10.2118/75503-MS Published: April 30 2002 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Get Permissions Search Site Citation Jokhio, Sarfraz A., and Djebbar Tiab. "Establishing Inflow Performance Relationship (IPR) for Gas Condensate Wells." Paper presented at the SPE Gas Technology Symposium, Calgary, Alberta, Canada, April 2002. doi: https://doi.org/10.2118/75503-MS Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAll ProceedingsSociety of Petroleum Engineers (SPE)SPE Unconventional Resources Conference / Gas Technology Symposium Search Advanced Search AbstractA new simple method of establishing Inflow Performance Relationship for gas condensate wells is proposed. The proposed method uses transient pressure test data to estimate effective permeability as function of pressure and then uses it to convert production BHFP data into pseudopressure to establish well performance. Requirement of relative permeability as function of saturation thus has been completely eliminated. Effective permeability of either phase can be used to predict the production of second phase. A scheme has also been devised to estimate the effective permeability using well testing mathematical models available in literature.Also mathematical models of well deliverability loss due to condensate deposition when dew point pressure is reached, and deliverability gain due to condensate mobility when P* is reached have been developed. Pseudopressure curves for both oil and gas phase have been developed for quick conversion of pressure data into pseudopressure. Relative permeability curves if available can also be used, however, the knowledge of saturation has to be known at all the stages of the depletion to be able to use them.Gas condensate reservoirs are primarily gas reservoirs. As the pressure declines with depletion, reservoir conditions of pressure may go below dew point and liquid begins to buildup. Such reservoirs may go under liquid buildup without showing any trace of liquid production. Sudden well deliverability loss and very high skin factor estimates from pressure tests are strong indicators of liquid buildup. PVT characteristics like phase diagram help identify the problem too. As the critical conditions are reached such reservoirs become two phase in nature.Finally, a field example is analyzed to show the use of new method developed and a step-by-step procedure is used to establish the well performance. Small operators, Independents, will benefit from this method at the most, since data acquisition like relative permeability curves require the laboratory experiments on cores, an expensive procedure.IntroductionRetrograde Gas-condensate systems have not been treated so intensively as solution gas reservoirs have been. Main reason is the phase behavior of light (C1-C10) hydrocarbons in the reservoirs. Retrograde gas-condensate reservoirs are primarily gas reservoirs. A zone of liquid begins to form as the dew point pressure is reached. The liquid keeps accumulating and does not flow until the critical liquid saturation is reached. Pressure at this point in the reservoir is termed P*. Interestingly, this liquid may re-vaporize as the pressure further crosses the lower line on two-phase envelope of phase diagram. This behavior of re-vaporization of the oil phase is called the "Retrograde behavior." Fig.2 through Fig.4 show the schematics of such phenomenon in vertical and horizontal well. Deliverability loss in such conditions is mainly due to two reasons:Gas undergoing liquid phase andpermeability impairment by the liquid. Thus both have to be handled mathematically to predict the well performance with reasonable accuracy. Keywords: flow rate, reservoir, gas phase pseudopressure, tiab spe 75503, derivative, drillstem testing, drillstem/well testing, effective permeability, oil phase, upstream oil & gas Subjects: Fluid Characterization, Formation Evaluation & Management, Phase behavior and PVT measurements, Drillstem/well testing This content is only available via PDF. 2002. Society of Petroleum Engineers You can access this article if you purchase or spend a download.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.006 | 0.019 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.004 | 0.003 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.003 | 0.004 |
| Open science | 0.001 | 0.003 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.020 | 0.006 |
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.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".