Chemical Enhanced Oil Recovery with polymer flooding allows to decrease the mobility ratio between oil and water and therefore increase the sweep efficiency in the reservoir through different mechanisms that take place, such as: pressure drops and viscosity changes of the injected fluid. The main objective of this work is to assess the friction factor coupled with the pressure drop evaluation, to define its impact in the polymer injection through porous media. The evaluation will allow the determination of the drag enhancement and drag reduction zones of the polymer solutions, which contributes to understand the additional oil recovery. A total of 12 polymer solutions were selected for this investigation and to establish numerical and experimental comparisons. Two types of commercial hydrolyzed polymers (Flopaam 6035S and Hengfloc 63023) were used at three different concentrations (500, 1000 and 1500 ppm). The polymer solutions were prepared using two different approaches (induced mechanical degradation and non-sheared). Experiments were performed injecting the polymer solutions in Bentheimer core samples. The evaluation was performed using a fourfold approach: 1) Three different rheological models were applied (Ergun (1949), Tiu et al. (1997) y Al Fariss (1990)), to determine mechanical parameters such as friction factor, Reynolds number and Weissenberg number.
Bosch, Miguel (Universidad Central de Venezuela) | Lacruz, Alberto (Pacific-Rubiales Energy) | Colmenares, Tibaire (Pacific-Rubiales Energy) | Salinas, Trino (Pacific-Rubiales Energy) | Yibirin, Rober (Pacific-Rubiales Energy) | Fuenmayor, Mac (Pacific-Rubiales Energy) | Zambrano, Sary (Info Geosciences Technology and Services)
The in-situ combustion is an Enhanced Oil Recovery process that affects reservoir rocks elastic properties. We have modeled the seismic response and the rock elastic properties modifications due to the heat generated by the combustion process in the reservoir and the substitution of original pore liquids by gases. Due to the changes of the elastic properties of the rock, two major effects in time-lapse seismic data are produced, both for PP and converted PS reflections: (1) reflectivity amplitude changes at the top and bottom of the reservoir up to the front of combustion and (2) time-shifts for reflectors in the zone affected by temperature changes and particularly beneath the reservoir. Our results show that the time-lapse seismic data is sensitive to the combustion process. In addition, there are basis for decoupling the temperature effect, mostly affecting time-shifts, and the combustion front propagation, mostly affecting reflectivity in the enclosed area delimited by the front. A field experiment made in one of the Llanos basin oil fields in Colombia with the deployment of time-lapse seismic monitoring confirms our results on the sensitivity of the method to map the progress of the in-situ combustion process.
Bosch, Miguel (Universidad Central de Venezuela) | Morales, Diego (Pacific-Rubiales Energy) | Gomez, Yohaney (Pacific-Rubiales Energy) | Kazmierczak, Thais (Pacific-Rubiales Energy) | Salinas, Trino (Pacific-Rubiales Energy) | Alvarez, Gabriel (Pacific-Rubiales Energy) | Moreno, Adriana (Info Geosciences Technology and Services) | Pino, Youleissy (Info Geosciences Technology and Services) | Medina, Edinson (Info Geosciences Technology and Services)
The contribution of seismic inversion to the description of a reservoir is specific to the geological setting and target formation. We have implemented various studies of reservoir characterization based on the results of elastic seismic inversion in areas of the Llanos basin in Colombia, with similar results regarding the contribution to the reservoir information at the basal levels of the Carbonera formation, the common target in this area. These studies have been particularly successful in the discrimination of the siliciclastic lithology (sand versus shale), estimation of the sand quality and have also provided satisfactory discrimination of oil bearing sands. Mass density is well related with the shale volume fraction due to the compaction of shale in basal levels of Carbonera. Furthermore, oil bearing sands are more likely characterized by low values of Poisson ratio, bulk modulus and Vp/Vs ratio. Our estimators of shale fraction, porosity and discriminators of oil-sands, based on elastic seismic inversion and fine calibration against well-log data, have revealed as an important predictive tool in the Llanos basin fields.
This paper presents a study of the reservoir simulation OFI INF SDZ-2X located in Zuata Main Field, Junin Division of the Orinoco Oil Belt to evaluate the incidence and extent of Electric Heating in downhole with heating cable technology as the mechanism of enhanced °API =10 oil recovery.
The proposed simulation model uses the historical data of JK2306 well to which was applied a pilot test with system of electrical heating turning out an increase in its production therefore decreasing viscosity from 14.500cp (120°F) to 3.500 (150°F) and improving rock-fluid and fluid-fluid properties of reservoir. Once the history of the production-before and after the electrical heating-was matched, values of the thermical variables were obtained of reservoir for the contribution of a second simulation model where production forecasts were made for 6 years from a sample of 4 wells of the RS19 cluster it was obtained a profile of increased production of it and the impact of technology in the recovery factor. Furthermore, an economic analysis was elaborated by checking the scenarios for which the application of the technology of heating cable in extra-heavy oil reservoir from the Orinoco Oil Belt is profitable.
Summary Lithologic discrimination was performed in clastic reservoirs in Orinoco Oil Belt, Venezuela, integrating rock physics, simultaneous seismic inversion and support vector machines. The rock physics analysis allowed to obtain relation between lithologic facies and elastic properties in reservoirs. Subsequently, through simultaneous seismic inversion was possible to generate P and S wave impedances and density volumes. Finally, combining the previous two points was generated a lithofacies volume using the algorithm of support vector machines as classification tool. Results of this study permitted to identify reservoir pay zones.
Bosch, Miguel (Universidad Central de Venezuela) | Justiniano, Adriana (Info Geosciences Technology and Services) | Alvarez, Gabriel (Pacific-Rubiales Energy) | Morales, Diego (Pacific-Rubiales Energy) | Azuaje, Vicmar (Pacific-Rubiales Energy) | Gomez, Yohaney (Pacific-Rubiales Energy) | de Souza, Thais (Pacific-Rubiales Energy)
Bosch, Miguel (Universidad Central de Venezuela) | Bertorelli, Gustavo (Pacific-Rubiales Energy) | Alvarez, Gabriel (Pacific-Rubiales Energy) | García, Eduardo (Pacific-Rubiales Energy) | Moreno, Adriana (Info Geosciences Technology and Services) | Colmenares, Raul (Info Geosciences Technology and Services)
Martinez, Dubraska (Universidad Central De Venezuela) | Guerrero, Angel E. (Chevron Venezuela) | Azuaje, Evelyn (Universidad Central de Venezuela) | Persad, Shelley Lucy (BG Trinidad & Tobago Ltd.) | Ramkissoon, Chris Farez (British Gas T&T Limited)
Rate dependent skin is a key factor influencing the deliverability of gas producing wells because of the phenomena of high velocity flow behavior around a limited, near wellbore cross-sectional area. Forchheimer (1901)  proposed an additional factor in Darcy's original equation to account for the pressure drop due to high velocity flux in the porous media, known as "Inertial Resistance Factor (ß)", which is now a determinant parameter in the flow modeling of gas wells. Several authors have developed different correlations that account for the inertial forces acting under these producing conditions.
Multi-rate and Pressure Transient Analysis (PTA) evaluation was performed on nine (9) gas well tests in the Dolphin Field. The Non- Darcy Flow Coefficient (NDFC) obtained was compared with predicted NDFC's using 18 Beta (ß) correlations, where each correlation has its own assumptions and determinant parameters.
Existing correlations do not match the actual NDFC in the field, as a consequence, a new Inertial Resistance Factor Correlation (IRFC) is proposed for assessing the unknown NDFC in the ECMA fields with a minimum percentage error of 17%.
The following study will detail the results of a probabilistic approach which uses correlations to provide a better estimate of NDFC in the Dolphin field, with the final objective of reducing uncertainty in forecasting production on recompletions and new wells in East Coast Marine Area fields.
Three dry gas fields are located within the East Coast Marine Area (ECMA) of Trinidad and Tobago: Dolphin, Dolphin Deep and Starfish. Found approximately 65km off Galeota Point (See Figure 1), Dolphin field was discovered in 1976 by Tenneco and started production in 1996. Meanwhile, Dolphin Deep and Starfish were both discovered in 1998, whereas Dolphin Deep commenced production in 2006 and Starfish is awaiting development in the near future.
Gas rate assessment is a constant concern in production modeling and reservoir potential evaluations. The starting point in gas rate assessments corresponds to the fluid flow equation known as Darcy's Law (H. Darcy, 1856). Unfortunately, Darcy's original equation does not correctly account for the pressure drop due to high gas velocities. Forchheimer (1901)  added an additional factor to Darcy's original equation to account for inertial forces which increase the pressure drop in high velocity flow. This factor, known as Inertial Resistance Factor is now widely applied in reservoir potential assessments and must be calibrated to reservoir conditions to increase accuracy in rate predictions as part of the Inflow Performance Relationship (IPR) input that determine the reservoir deliverability.
During this evaluation 18 correlations were assessed to determine the representative correlation to apply to the field. The correlation with minimum error between actual rate dependent skin and correlation calculated rate dependent skin was selected.