Measuring device and measuring method for core porosity

Abstract

The invention discloses a measuring device for core porosity. The measuring device comprises a helium cylinder tank, a pressure reducing valve, a sample chamber, a reference chamber, a pressure sensor, a digital display meter, a first valve, a second valve and a third valve; the situation of enabling helium to enter the sample chamber at first and then enter the reference chamber can be realized through the valves. The invention also discloses a measuring method for the core porosity. The measuring method comprises the following steps: (1) calibration: leading the helium into the sample chamber at first, then leading the helium into the reference chamber through pressure differentiation, and calculating to obtain reference chamber volume Vr and sample chamber volume Vc through a simultaneous equation, wherein the calibration is completed by repeating for many times; (2) measurement: calculating to obtain the core porosity through the simultaneous equation. According to the measuring device and the measuring method, disclosed by the invention, by leading high-pressure to-be-measured helium into the sample chamber at first and then leading the helium into the reference chamber through pressure differentiation, the pressure variation before and after the pressure differentiation can be remarkably increased, and the pressure variation is increased while the core pore volume is reduced; under the same device condition, the porosity of a core sample, particularly a low-porosity sample, can be more accurately measured by adopting the measuring device and the measuring method.

Description

technical field [0001] The invention relates to a rock core porosity measuring device and a measuring method, in particular to a rock core porosity measuring device and a measuring method in which measuring gas first enters a sample chamber and then enters a reference chamber under partial pressure. Background technique [0002] The current mainstream core porosity measurement methods at home and abroad mainly adopt the oil and gas industry standard SY / T5336-2006 "Core Analysis Methods" (ie API RP 40: 1998, Recommended Practices for CoreAnalysis, the Chinese imported version of IDT), 5.3.2.1.1 Boyle’s law double-chamber method (rock sample cup) to measure particle volume and 5.2.3 Caliper measurement method to measure the apparent volume of regular cores, the difference between the apparent volume minus the particle volume divided by the apparent volume is Porosity. [0003] In theory, the above method can measure regular core samples of any size and porosity; but in practi...

AI Technical Summary

Problems solved by technology

[0009] In summary, the Boyle’s law double-chamber method (rock sample cup) recommended by SY / T 5336-2006 to measure particle volume, when measuring low-porosity samples such as shale (porosity is usually 0-2%), the measurement results The error is large, which affects the follow-up test and research

Images