Method for evaluating plugging effect of drilling fluid for crack expansion type leakage reservoir

• Main Authors: DENG SONG, LI CHAOWEI, YAN XIAOPENG, HAO HONGDA, WANG JIANGSHUAI
• Format: Patent
• Language: Chinese; English
• Published: 14.03.2023
• Subjects: EARTH DRILLING; EARTH DRILLING, e.g. DEEP DRILLING; FIXED CONSTRUCTIONS; INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIRCHEMICAL OR PHYSICAL PROPERTIES; MEASURING; MINING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR ASLURRY OF MINERALS FROM WELLS; PHYSICS; TESTING

The invention discloses a method for evaluating the plugging effect of drilling fluid for a crack expansion type leakage reservoir. The method comprises the following steps: determining the gas logging initial permeability of a core in a research target area by utilizing the Darcy law; placing a to-be-evaluated drilling fluid into the roller furnace, performing hot rolling at the formation temperature, pouring the to-be-evaluated drilling fluid into the intermediate container, opening a valve at the outlet end of the core holder, displacing the drilling fluid in a constant-pressure manner, and recording the invasion amount of the drilling fluid at different displacement time; determining the plugging layer forming time and the plugging layer average permeability of the drilling fluid according to the invasion amount of the drilling fluid; evaluating the plugging effect of the drilling fluid through the plugging efficiency coefficient of the drilling fluid; compared with a traditional method, the method provid