Abstract

The authors consider the technology for monitoring of shallow super-viscous oil (SVO) deposit development process aimed to determine the heated zones distribution corresponding to the drainage areas to enhance the efficiency of development process based on steam injection. The main objective of the work is to develop the monitoring approach based on downhole receivers and interpret the results of surface geophysical survey conducted with the use of downhole receiver tools.

The downhole monitoring tools (receivers) are used to improve the sensitivity of the method and to decrease the environmental influence. Each tool includes 3 geophones located in metal case and is connected with the surface by wireline. The tools are set in the bottom hole of evaluation wells and the wells are abandoned. There are several factors influencing the seismic wave velocities (temperature, pressure, saturation etc). To provide more adequate interpretation geophysical methods with different nature are were to use in complex. The surface monitoring methods considered include shallow seismic prospecting and electrical prospecting.

The results of periodical geophysical investigation are the maps of seismic wave propagation delay from surface source to the downhole receivers, electrode resistivity maps and interwell resistivity maps for different moments of time.

Basing on the change of seismic wave ray velocity the heated regions are identified and the type of fluid saturation estimated with the use of resistivity mapping. The results obtained were used for the development planning including the injection pipe positioning.

The interpretation results in terms of heated zones location obtained in the area of study was compared with the direct temperature measurements by periodical optical fiber thermometry conducted in horizontal producer wells.

The possibility of steam injection process monitoring by surface geophysics with downhole receiver tools is shown basing on the real field case of shallow super-viscous oil deposit.

The relations between geophysical fields considered and reservoir characteristics (temperature, saturation, pressure) are discussed.

The work was supported by the Ministry of Science and Higher Education of the Russian Federation (project No. 02.G25.31.0170) and by the subsidy allocated to Kazan Federal University as part of the state program for increasing its competitiveness among the world's leading centers of science and education.

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