High-temperature and high-pressure shale oil reservoir imbibition evaluation device

Abstract

The invention discloses a high-temperature and high-pressure shale oil reservoir imbibition evaluation device and relates to the technical field of compact oilfield oil extraction evaluation. A compression sleeve is arranged at the bottom of a pressure tank, a rock core is arranged in the compression sleeve, a fracturing pipe is inserted into a counter bore of the rock core above the rock core, the fracturing pipe extends upwards to penetrate through the compression sleeve and is connected with the compression sleeve in a sealed mode, and the fracturing pipe penetrates through a flange cover of the pressure tank and is connected with the flange cover in a sealed mode. The high-temperature and high-pressure shale oil reservoir imbibition evaluation device has the following beneficial effects: the compression sleeve is arranged to separate the rock core from the outer part, an oil reservoir in the rock core does not leak, the external pressure and temperature can act on the rock core, the rock core can be kept balanced under pressure through a pressure balancer, the oil-water distribution in gaps of the compact oil reservoir rock core does not change, the processes of fracturing fluid injection into the stratum, soaking and imbibition replacement oil extraction are simulated, important influences are generated on fracturing fluid component optimization, soaking time determinationand imbibition mechanism research, and effective experimental equipment is provided for a rock core imbibition experiment in a high-temperature and high-pressure environment.

Description

Technical field: [0001] The invention relates to the technical field of tight oil field oil recovery evaluation, in particular to a high-temperature and high-pressure shale oil reservoir imbibition evaluation device. Background technique: [0002] Tight oil resources are extremely abundant at home and abroad. Due to the extremely low matrix permeability of tight oil reservoirs, the current mainstream development method at home and abroad relying on the energy depletion of natural formations can only use crude oil in the vicinity of fractures communicated by artificial fracture networks. The ultimate recovery of the reservoir can only reach 3-10% at most, and the use of surfactants to change the wettability of the reservoir to enhance the recovery has long been used in the development of conventional multi-fractured carbonate reservoirs , in order to promote the imbibition of the matrix by changing the wettability of the reservoir in the process of water flooding, so that the...

AI Technical Summary

Problems solved by technology

[0006] Since the 1980s, the United States has developed pressure-holding sealed coring, so that the cores taken out are not affected by mud, and can maintain fluid saturation under formation pressure conditions. This technology has also been successfully studied in China, but the process of this method Complex and very costly;

[0007] Tight oil reservoirs are oil reservoirs without natural productivity, and the loss of oil may not be considered when the core is taken out, but it is necessary to pay attention to the distribution of the reservoir caused by the loss of pressure at the edge of the core, which needs to be corrected on the experimental data, or pressurized to make it re- Returning to the original state, the current imbibition evaluation test devices have not noticed the experimental error caused by the pressure difference. For example, the core imbibition experiments of invention CN107101925A and invention CN104020098A are obvious. In the scene of water immersion, soaking the core directly in water at the same time will easily cause the capillary force to offset, resulting in experimental errors, or the imbibition experiment is carried out without simulating the bottom pressure and temperature, resulting in distortion of the experimental data, which is far lower than that of the United States. The experimental data obtained by pressure-holding and sealed coring is the technical bottleneck of tight oil reservoir imbibition evaluation in my country

Images