China National Petroleum Corporation (China)

Liquid CO2 Replacement and SequestrationBehavior after Depressurization Production of Methane Hydrates

Abstract Aligned with China’s “dual carbon” strategic objectives, natural gas hydrates─recognized as a crucial source of clean unconventional natural gas─constitute a significant technological avenue for securing national energy stability and meeting carbon reduction targets thro...

Diagenesis of UpperTriassic Chang 8 Sandstones, SouthwesternOrdos Basin, China: A New Insight into the Formation Mechanism ofChlorite and Calcite Cement

Abstract Authigenic minerals from Chang 8 sandstones can preserve a precise paleotemperature record. Petrographic observations and geochemical characteristics provide a new insight into the formation mechanism of chlorite and calcite and resolve the problems of mobile elements be...

Preparation of Salt‐Resistant Gemini Surfactants via Ethylene Oxide Group Regulation for Enhanced Oil Recovery

ABSTRACT Conventional anionic surfactants generally exhibit poor salt tolerance and reduced interfacial activity under high‐salinity reservoir conditions, limiting their application in enhanced oil recovery (EOR). To address this issue, a series of anionic–nonionic isotridecanol...

Research on Calculation Methods for Flow Distribution and Pressure Loss of Reaming-While-Drilling (RWD) Tools

As global oil and gas exploration advances into deep reservoirs, reaming-while-drilling (RWD) tools (hereinafter referred to as the reamer) are widely used to enlarge wellbores for unconventional well structures, prevent stuck pipe caused by formation shrinkage, and improve cemen...

Control Mechanism of Water Shield on Pressure Dynamics of CO2 Huff-n-Puff and Crude Oil Mobilization Effect in Tight Reservoirs

Tight oil reservoirs are characterized by poor petrophysical properties, ultra-low permeability, and limited pressure-transmission capacity. After hydraulic fracturing, retained fracturing fluid can accumulate near the fracture–matrix interface and form a water shield, which rest...

Research on the Microscopic Residual Oil Activation Mechanism of Heavy Oil in Different Water Content Stages

This paper investigates the occurrence characteristics, mobilization behavior, and controlling mechanisms of microscopic remaining oil in heavy-oil systems at different water-cut stages by using a visual microfluidic platform. A series of displacement and pressure-ramping experim...