Heat Management for Steamflooding Projects

Trigos Becerra, Erika M.¹; Rueda, Silvia F.; and Rodríguez, Edwin
¹[email protected]

Some works have shown the application and relevance of heat management in steam flooding projects. This concept begins from the understanding of the process stages and the identification of the energetic requirements of each one of them, to avoid misspends the energy. Based on field an experience like Duri (Ziegler, 1993) and Kern River (Gael, 1994) fields is easy to recognize that the best implementation strategy varies according to the reservoir characteristics.

Considering that in Colombia there are some reservoirs with presence of interbedded shale and a long history of cycles of steam stimulation, was conducted a research using numerical simulation to determine the best scenarios for steam flooding implementation, which includes a sensibility analysis taking into account, injection rate, wells spacing, selective injection strings technology, partial interval perforating as a strategy of delay the steam breakthrough in the producing well and finally strategies of heat management like periodic reduction of the injection rate and programmed shut-in of injection Wells. The oilfield on study is located at the Magdalena Middle Valley (Colombia).

This oilfield produces heavy oil of 12.5°API by cyclic steam stimulation (CSS) and the oil recovery factor is 15%. The reservoir produces from a multiple sand reservoir with Interbedded shale. Shale has a high volumetric heat capacity, for this reason it act like an energy thief in a thermal process. Nevertheless, CSS has been successful for fifteen cycles, but at the moment, the process has lost effectiveness, for the reason, is the time to change to steam flooding.

The final results showed eight possible implementation scenarios, that later will be compared from an economic perspective to identify the ideal scenario for the field conditions. Simulation results shows that high injection rate (700 bbls/injection well) in patterns of 2.5 acres produced the highest incremental production from cold production, reaching about two million barrels of oil in 10 years, however this production is associated with very high cumulative steam oil ratio (cSOR) near to 13, the best strategy to reduce cSOR was the periodic reduction on injection rate reaching a ratio of 11. Furthermore it was identified that the time of evaluation of the project as one of the most influential parameters to establish the heat management strategies.

AAPG Search and Discovery Article #90166©2013 AAPG International Conference & Exhibition, Cartagena, Colombia, 8-11 September 2013