Experimental device and evaluation method for simulating scouring and dissolving effects of cement paste on salt rocks

Abstract

The invention discloses an experimental device and an evaluation method for simulating the scouring and dissolving effects of cement paste on salt rocks. The device comprises a cement slurry tank, anda heating instrument with a water bath box is arranged below the cement slurry tank; the cement slurry tank is connected with a pneumatic diaphragm pump; the pneumatic diaphragm pump is communicatedwith a flushing device through a corrugated pipe; and the flushing device is communicated with the cement slurry tank through the corrugated pipe. The invention is reasonable in design and convenientto operate, can quantitatively analyze the scouring degree of cement paste to stratum rocks at different flow rates, temperatures and times, can research action mechanisms of the cement paste and thesalt rocks, and can judge whether the cement paste system can still keep good design performance after being in contact with the salt rocks, so that a certain experimental basis is provided for the design of the cement paste system, the prediction of the change range of the cement paste performance and the optimization of cementing construction parameters, thereby improving the well cementation quality.

Description

technical field [0001] The invention relates to the field of cementing technology, in particular to an experimental device and an evaluation method for simulating the erosion and dissolution of cement slurry on salt rock. Background technique [0002] For gypsum layer cementing, the design of the cement slurry system cannot be considered as conventional cement slurry. Since the gypsum layer is mainly composed of gypsum rock, salt rock and mud shale interlayer, the salt layer must be considered in the process of designing the cement slurry system. The influence of dissolution on the performance of cement slurry requires a certain understanding of the amount of dissolution under different conditions. [0003] Drilling to open the formation will destroy the original formation stress and form a large stress concentration near the wellbore. During the cementing process, the cement slurry will generate a certain shear force on the wellbore wall due to its certain viscosity. For h...

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Problems solved by technology

[0005] In the above-mentioned device, since the core support is sleeved in the core, it is very inconvenient to replace and disassemble the core in this way. No matter whether it is to replace the core support or the core, both of them need to be disassembled. This undoubtedly increases the workload of the staff. In addition, during the experiment, due to the different lengths of the selected rock cores, the length of the through cavity in the reactor body cannot be adjusted to match the length of the rock core, which has great limitations and cannot meet higher requirements. Experimental requirements

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