Method and device for detecting water quality of oilfield water injection wellbore in situ

Abstract

The invention discloses a method for detecting the water quality of an oilfield water injection wellbore in situ. A laser light source is arranged on the ground, light is coupled into a large-caliber heat-resistant optical fiber through an optical fiber collimator and is connected with a transmitting optical fiber micro lens on an integrated probe, which is arranged on an oil pipe and is provided with a transmitting optical fiber micro lens and a receiving optical fiber micro lens opposite to each other; the emitted light is focused to high-temperature high-pressure liquid and particles through the transmitting optical fiber micro lens; scattered light is received by the receiving optical fiber micro lens arranged in multiple angles and is transmitted to a ground processor through an optical fiber; the processor measures the signal intensity of the scattered light through multiple detectors respectively, and finally, multi-parameter water quality detection is finished through a signal acquisition and processing system. Detected data is input into water quality corrosion and scaling tendency prediction software, a variation tendency of the water quality and corrosion scaling is predicted according to change of parameters such as temperature and pressure in a process of injecting reinjection water, main reasons of the water quality change are determined, and corresponding water quality stability control measures are provided.

Description

technical field [0001] The invention relates to a method and device for in-situ detection of water quality in an oilfield water injection wellbore, specifically, how to properly use laser to detect water quality data and compare the water quality prediction data to accurately reflect the reinjection water in the injection process of the water injection wellbore and after it is injected into the formation According to this change trend, corresponding water quality stabilization control measures are put forward to reduce the damage degree of water quality to the formation. Background technique [0002] Waterflood development of oilfields is a widely used and effective development method in the world. In the process of water injection, the quality of the injection water directly affects the development effect of the oil field. However, during the transportation process of the water injection system after the sewage is treated by the treatment station, due to reasons such as co...

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Problems solved by technology

[0003] Aiming at the current situation that the water quality in the oilfield water injection wellbore changes at different depths and in high temperature and high pressure environments and affects the water injection effect, the present invention uses high-precision laser detection and analysis technology to develop a water injection wellbore water quality turbidity, particle size distribution and ion concentration. The detection method and device have certain innovations:

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