Portable spontaneous imbibition measuring device

Abstract

The invention discloses portable spontaneous imbibition measuring device which comprises a drying chamber and a measuring chamber, wherein a temperature sensor I and a heating device I are arranged in the drying chamber, and a ventilation opening is formed in the side wall of the drying chamber; a temperature sensor II and a heating device II are arranged in the measuring chamber, and a weighing module is further arranged at the bottom of the measuring chamber; a stress sensor and a container rack are arranged in the weighing module and at the bottom of the measuring chamber, and the container rack is arranged above the stress sensor and is not contacted with the stress sensor; a container is fixed on the container rack; a rock sample suspension rack is arranged on the stress sensor, and a suspension rope is suspended on the rock sample suspension rack, is used for suspending a to-be-measured rock sample and extends deeply in the container; and the stress sensor is connected with a signal output end. The portable spontaneous imbibition measuring device can measure change relationship of the quality of a fracturing fluid absorbed by the rock sample at constant temperature and normal pressure over time, so that technical indexes such as the water absorption rate, capillary force, water absorption quantity and the like of the rock sample can be known from research of the spontaneous imbibition.

Description

technical field [0001] The invention relates to a portable spontaneous imbibition measuring device, which belongs to the fields of oil and gas field development and porous medium seepage mechanism research. Background technique [0002] With the continuous discovery and experimental development of unconventional natural gas resources, research on unconventional natural gas resources is deepening. At present, in the research of tight reservoirs, especially low-porosity and low-permeability shale gas reservoirs, evaluating the spontaneous imbibition strength of reservoir rocks is one of the research focuses. First of all, due to the small throats of low-permeability reservoirs, most of which are at the micro-nano level, the spontaneous imbibition phenomenon caused by capillary force is more obvious than that of conventional reservoirs, and has a greater impact on the reservoir. Secondly, the water absorption capacity of low-permeability reservoirs depends on lithology, format...

AI Technical Summary

Problems solved by technology

[0005] The above-mentioned method has the following disadvantages: firstly, the core spontaneous imbibition experiment is carried out by this scheme, and the rock sample needs to be processed into a standard core after drilling, grinding and other processes. Obviously, the cuttings on site cannot meet the core preparation requirements of this scheme. , if operations such as bottom hole or hole wall coring are carried out, the cost of the experiment will be greatly increased

Secondly, if the spontaneous water absorption of the rock is not large, the error defect of this plan will be obvious, because the diameter of the glass tube is limited by the manufacturing process, if it is too thick, the change of the liquid level will not be obvious, if it is too thin, the glass tube itself will produce obvious capillaries If the water surface rises too high, the laboratory space and the glass tube manufacturing process will not meet the requirements. In addition, the upper part of the glass tube must be connected to the atmosphere, and the water in the tube will inevitably evaporate, which will cause the page of the metering tube to drop and affect the experimental results.

Finally, the rock will expel the gas inside the rock in the form of air bubbles during the process of water absorption. From the structure of the experimental instrument, it cannot guarantee that the air bubbles will be discharged from the thin glass tube, which also affects the accuracy of the experiment.

[0006] It can be seen that the conventional self-priming evaluation method needs to process the core and send it to the laboratory for analysis and evaluation, which often takes a long period and the number of samples is too small, which is poor in representativeness for unconventional reservoirs with stronger heterogeneity. Therefore, it is necessary to invent a device that can quickly, easily and economically evaluate the spontaneous imbibition capacity of tight reservoir rocks in different formations or in different positions in the same formation, so as to be widely used in volume fracturing fracturing fluid fluid loss and Flowback analysis, tight reservoir evaluation and protection, water flooding reservoir and fractured reservoir development research

Images