Predicting Downhole Fluid Analysis Logs to Investigate Reservoir Connectivity

Betancourt, Soraya S.; Dubost, Francois Xavier; Mullins, Oliver C.; Cribbs, Myrt Eugene; Creek, Jefferson L.; Mathews, Syriac George

doi:10.2523/11488-ms

Cited by 14 publications

(3 citation statements)

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“…The use of asphaltene gradients identified with DFA to investigate reservoir connectivity stems from work in the Tahiti field (Betancourt et al 2007). Similar to Wilcox, Tahiti fluids have low GOR and minor compositional variations.…”

Section: Dfa Technologymentioning

confidence: 99%

Understanding Fluid Complexity and Reservoir Connectivity Using Downhole Fluid Analysis in Wilcox Formation Gulf of Mexico

Betancourt

Mishra

Clinch

et al. 2016

Day 2 Tue, May 03, 2016

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The development of the Wilcox formation in the Gulf of Mexico is constantly pushing technical boundaries in the oil industry. Here, ultra-deepwater wells are needed to target ultra-high pressure sub-salt reservoirs that are up to 32,000 ft below sea level. Innovative evaluation techniques and processes that could reduce reservoir uncertainties are key from prospect evaluation through field appraisal and development. In particular, detailed description of reservoir properties, fluid characterization and connectivity assessment in this challenging environment are extremely valuable.An operator is extensively utilizing wireline formation tester measurements and downhole fluid analysis (DFA), and has implemented a workflow to assess reservoir connectivity using DFA data, asphaltene nanoscience, and geochemistry in a multi-well context. The coupling of vertical and lateral fluid gradient measurements from DFA and thermodynamic equilibrium analysis of the reservoir fluids represents a powerful new method for connectivity assessment. This includes use of novel asphaltene science and the Flory-Huggins-Zuo equation of state to model equilibrium asphaltene concentration gradients in petroleum reservoirs.The workflow has been successfully implemented in all the operator's Wilcox fields to appraise both vertical connectivity of reservoir sands within individual wells and lateral connectivity throughout the field, and identify potential production challenges associated with non-equilibrated fluids. These workflows hinge on the application of the latest formation testing technology to help acquire the nearly pristine formation fluid samples required for such DFA field studies and real-time decision-making in characterizing reservoirs.

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Section: Dfa Technologymentioning

confidence: 99%

Understanding Fluid Complexity and Reservoir Connectivity Using Downhole Fluid Analysis in Wilcox Formation Gulf of Mexico

Betancourt

Mishra

Clinch

et al. 2016

Day 2 Tue, May 03, 2016

Self Cite

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“…1,4,5 Estudos indicam que a precipitação de asfaltenos também pode ocorrer espontaneamente nos reservatórios, levando à formação de nanopartículas, principalmente quando essa fração está presente em baixas concentrações (< 0,1 g L -1 ). [6][7][8] Esse fenômeno, no entanto, normalmente está relacionado à produção/recuperação do petróleo, principalmente devido a variações de temperatura e à despressurização, comum nesses processos. [9][10][11][12] Na prática, uma das razões mais frequentes para a ocorrência desse fenômeno in situ é a injeção de gases (CO 2 , N 2 , hidrocarbonetos leves, gás natural) nos processos de recuperação avançada, ou métodos especiais de recuperação do petróleo.…”

Section: Introductionunclassified

Avaliação De Asfaltenos Precipitados Em Diferentes Condições De Composição, Temperatura E Pressão

Moura¹,

Rosa²

2017

Quim. Nova

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EVALUATION OF ASPHALTENE PRECIPITATION IN DIFFERENT CONDITIONS OF COMPOSITION, TEMPERATURE, AND PRESSION.Asphaltenes are a heavy fraction of petroleum with the ability for self-association, a phenomenon that can occur spontaneously in the reservoirs or in any of the various stages of production and processing, depending on variations in pressure, temperature, composition and shearing, among others. In this work, it was evaluated the precipitation of asphaltenes in two oils (P01 and P02) in different conditions of temperature and pressure and in the absence or presence of CO 2 . Under high pressure and temperature conditions, the precipitation of asphaltenes was observed in the presence of CO 2 in mixtures with methane, while the addition of propane induced precipitation in the absence of CO 2 . The results of analyses elemental (CHNO), SEM, FTIR and LDI-MS were consistent with the structure assigned to samples of this nature (oils, maltenes and fractions of asphaltenes insoluble in n-pentane, C5I, and n-heptane, C7I).Keywords: asphaltenes; precipitation; characterization; carbon dioxide; light alkanes. INTRODUÇÃOO petróleo é uma mistura complexa constituída de hidrocarbonetos saturados, aromáticos, resinas e asfaltenos.1,2 O sistema polidisperso formado pelo petróleo normalmente está em condições de equilíbrio, mas perturbações como variações de composição, temperatura e pressão, podem induzir a precipitação dos asfaltenos. 2,3Outros fatores como cisalhamento e efeitos eletrocinéticos aparentemente também exercem este efeito. 1,4,5 Estudos indicam que a precipitação de asfaltenos também pode ocorrer espontaneamente nos reservatórios, levando à formação de nanopartículas, principalmente quando essa fração está presente em baixas concentrações (< 0,1 g L -1).6-8 Esse fenômeno, no entanto, normalmente está relacionado à produção/recuperação do petróleo, principalmente devido a variações de temperatura e à despressurização, comum nesses processos.9-12 Na prática, uma das razões mais frequentes para a ocorrência desse fenômeno in situ é a injeção de gases (CO 2 , N 2 , hidrocarbonetos leves, gás natural) nos processos de recuperação avançada, ou métodos especiais de recuperação do petróleo. 10,[13][14][15][16] Nos petróleos brasileiros são pouco comuns problemas de precipitação de asfaltenos, mas estudos indicam que este fenômeno deve ocorrer nos campos do pré-sal, devido à injeção de CO 2 prevista para esses poços.12,17,16 Além de ser um fluido de injeção nos processos de recuperação, o CO 2 é um dos constituintes do gás natural e do próprio petróleo, geralmente presente em concentrações entre traços e 5% (em mol), 18 podendo, contudo, chegar a concentrações mais elevadas, como cerca de 20% (em volume) nos reservatórios do pré-sal. 19Em alguns processos de recuperação do petróleo, a precipitação dos asfaltenos é desejada, como no VAPEX, um dos processos baseados no uso de solventes no qual propano (puro ou como componente majoritário de uma mistura de hidrocarbonetos leves) é injetado em reservatórios para a diluiçã...

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“…The development of these tools was to address several production problems (e.g., sizing of facilities, well placement, completions equipment, and production prediction). According to Betancourt et al (2004Betancourt et al ( , 2007, the Composition Fluid Analyzer (CFA) is a tool which has a sensor for performing fluorescence spectroscopy by measuring light emission in the green and red ranges of the spectrum after excitation with blue light. It was originally introduced in order to track phase transitions in gas condensate sampling.…”

Section: Down-hole Fluid Analysismentioning

confidence: 99%

A regression model for estimation of dew point pressure from down-hole fluid analyzer data

Alzahabi

El-Banbi

Trindade

et al. 2017

J Petrol Explor Prod Technol

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Accurate knowledge of dew point pressure is important in understanding and managing gas condensate reservoirs. Without a correct assessment of dew point pressure, an accurate description of phase changes and phase behavior cannot be achieved. Numerous models for predicting gas condensate dew point pressure from surface fluid data have been proposed in the literature. Some of these require knowledge of the full composition of the reservoir fluid (based on laboratory experiments), while others only need field parameters that are relatively easy to obtain. This paper presents a new model for predicting the dew point pressure from down-hole fluid analyzer data. Such data are now measured (usually in real time) while obtaining down-hole fluid samples. The new model predictions give a quick estimation of dew point pressure for wet gas and gas condensate reservoirs. Since it relies only on down-hole measured data, the model provides an estimate of dew point pressure without the need for laboratory analyses. During down-hole fluid sampling, the model can be used to ensure whether the sample is still in single phase, or whether the dew point was crossed during the sampling operation. An early estimate of dew point pressure is also valuable in designing further tests for gas condensate wells. The new model, constructed using a fluid database of nearly 700 gas condensate samples, was devised using sophisticated statistical/machine learning methods, and attained a mean absolute relative error value of 2% for predicting the logarithm of pressure. In comparison with other dew point estimation models (that use surface fluid data), the chosen model was found to attain a similar level of accuracy when tested on samples not used in the model building phase.

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Predicting Downhole Fluid Analysis Logs to Investigate Reservoir Connectivity

Cited by 14 publications

References 0 publications

Understanding Fluid Complexity and Reservoir Connectivity Using Downhole Fluid Analysis in Wilcox Formation Gulf of Mexico

Understanding Fluid Complexity and Reservoir Connectivity Using Downhole Fluid Analysis in Wilcox Formation Gulf of Mexico

Avaliação De Asfaltenos Precipitados Em Diferentes Condições De Composição, Temperatura E Pressão

A regression model for estimation of dew point pressure from down-hole fluid analyzer data

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