Improvement and effectiveness analysis of dynamic/static imbibition experiments.

In low-permeability fractured reservoirs, there is a generalized fluid displacement between the replacement fluid in the fracture and the matrix crude oil. This imbibition behavior plays a crucial role in the development of this type of reservoir. The experimental devices for studying static imbibition behavior are generally susceptible to air pollution on the surface of the test core and a long testing period; the experimental devices for studying dynamic imbibition behavior are generally unable to eliminate the driving action.

Influence of Supercritical CO Fracturing Fluid on the Permeability of Shale Reservoir and Mechanism Analysis.

Reduction of the reservoir permeability during supercritical CO fracturing caused significant reservoir damage, which directly affects the crude oil recovery rate. This investigation explored a novel thickener for supercritical CO fracturing fluid, this CO thickener not only effectively improves the viscosity and rheological properties of CO fracturing fluid but also contributes to reduce reservoir damage and improve permeability. The research results indicated that the synthesized CO thickener (3 wt %) can increase the apparent viscosity of supercritical CO fracturing fluid to 7 mPa·s, and a 9% matrix permeability damage rate and a 0.

Characterized Functional Groups of Temperature- and Salt-Resistant Copolymers and Surfactants and Their Relationships.

As the physical properties of newly discovered oil and gas reservoirs become more complex and the requirements for field development effectiveness continue to increase, the performance of polymers and surfactants, which are commonly used as chemical agents in oil field development, is facing great challenges. The determinations of temperature and salt resistance of anti-temperature and anti-salt viscosity-enhancing copolymers and low-interfacial-tension surfactants in recent years have been reviewed. The mechanism of temperature and salt resistance of distinct functional groups was discussed, and the common functional groups of temperature- and salt-resistant viscosity-increasing copolymers and temperature- and salt-resistant low-interfacial-tension surfactants were pointed out.

Testing and Evaluation of the Emulsifying Properties of Compound Oil Displacement Agents.

Aiming at the phenomenon that the emulsification degree of the composite oil displacement agents affects the recovery factor, composite oil displacement agents of the P/S binary system and the A/S/P ternary system were taken as research objects. Emulsion particle size and stability were tested and evaluated, and the effects of the surfactant and alkali content on the emulsification degree of emulsion were investigated. The concept of the emulsification stability index and its measuring method were put forward, and a method was used to test and evaluate the emulsification stability of the emulsion.

Spontaneous Imbibition of Capillaries under the End Effect and Wetting Hysteresis.

The phenomenon of spontaneous imbibition is widely present in the development process of tight oil/gas reservoirs. To further explore the spontaneous imbibition behavior of capillary tubes to provide theoretical and methodological references for the study of microscopic porous media imbibition phenomena, the capillaries that can be observed with the naked eye on the order of 10-100 μm were selected as research objects. Based on the theory of interface chemistry, the capillary end effect, and wetting hysteresis, the influence of the additional pressures generated by the two-phase interface on the spontaneous absorption of the horizontal capillary was studied.

Endonasal endoscopic repair of cerebrospinal fluid rhinorrhea in a series of 69 patients.

We presented our experiences in treatment of Cerebrospinal Fluid (CSF) rhinorrhea with an endoscopic endonasal surgery approach, and showed the severe postoperative complications and failures we experienced, in order to outline some of the characteristic problems that can occur. We performed a retrospective analysis of all of the patients with CSF rhinorrhea. All of the patients were managed with an endonasal endoscopic procedure.

[Anesthesia selection in hypophysectomy by endoscopic transnasal sphenoidal approach].

Objective: To explore the anesthesia selection in resection of pituitary neoplasms by endoscopic transnasal sphenoidal approach.

Method: Fifty-six cases with pituitary tumor underwent transnasal sphenoidal endoscopic surgery . Among the 56 cases, 8 cases accepted general anesthesia and 48 cases accepted local anesthesia and sedation.

[Anatomic study of pterygopalatine fossa under endoscope].

Objective: To provide endoscopic anatomic bony structures of pterygopalatine fossa for skull base surgery.

Methods: The bony structures of the pterygopalatine fossa were observed in ten dry skulls under endoscope.

Results: The pterygopalatine fossa showed a long and narrow cleft composed of the body and pterygoid process of sphenoid bone, the lamina perpendicular of palatine bone, and the posterior wall of maxillary sinus.