Lost Circulation Prediction Method Based on an Improved Fruit Fly Algorithm for Support Vector Machine Optimization.

Lost circulation events during drilling operations are known for their abruptness and are difficult to control. Traditional diagnostic methods rely on qualitative indicators, such as mud pit volume changes or anomalous logging curve patterns. However, these methods are subjective and rely heavily on empirical knowledge, resulting in delayed or inaccurate predictions.

Wellbore Flow Model and Process Optimization for Gas-Lift Leakage Drilling for Shallow Shale Formations.

The shallow surface karst landform in the Nanchuan-China shale gas area, with developed caves and underground rivers, frequently lost circulation during the drilling operation. To solve the issue, first, according to the actual drilling engineering, this paper analyzes the geological factors and drilling and completion characteristics, optimizes the construction plan, and suggests a new technology for gas-lift leakage drilling based on double-wall drill pipes. Second, a distributed coupling improved Beggs-Brill gas-liquid-solid multiphase flow model is established.