A core magnetic signal acquisition and inversion method adopting an ME-CPMG sequence

• Main Authors: GE XINMIN, FAN YIREN, WU FEI, LI CHAOLIU, HU FALONG, LIU JIANYU, XING DONGHUI
• Format: Patent
• Language: Chinese; English
• Published: 09.11.2016
• Subjects: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIRCHEMICAL OR PHYSICAL PROPERTIES; MEASURING; PHYSICS; TESTING

A core magnetic signal acquisition and inversion method adopting an ME-CPMG sequence is disclosed. The method includes setting waiting time under a constant magnetic field condition to completely polarize protons in a sample to the Z axis, bringing macroscopic magnetization vectors down to an XY plane by applying 90-degree radio frequency pulses, applying a series of 180-degree radio frequency pulses, and collecting magnetization vectors between adjacent two 180-degree radio frequency pulses. Different from CPMG pulses, the time interval of the adjacent two 180-degree radio frequency pulses can be changed according to prior information of the sample to be tested and user demands, and generally increases along with increases of sampling time. The ME-CPMG pulse sequence reduces the number of the 180-degree radio frequency pulses, effectively saves energy essential for signal excitation and data storage space, and increases the inversion speed. The method has a high application prospect in cores with weak relaxa