Synthesis and Performance Evaluation of an Organic/Inorganic Composite Gel Plugging System for Offshore Oilfields

Abstract

In this article, we developed a new composite gel for plugging dominant fluid flow channels in offshore oilfields. The composite gel was synthesized by organic and inorganic gel networks interpenetrating into a compact three-dimensional spatial network structure, resulting in a good plugging effect. The performance of the composite gel was evaluated from the aspects of gelling characteristics and gel microstructure, while the plugging effect was evaluated through core experiments. The results showed that the influencing order of each component on gelling was acrylamide > cross-linking agent > urea > initiator > polyaluminum chloride. The initial viscosity of the composite gel was about 5–6 mPa·s, and it had good plugging abilities in different permeability cores. In comparison with inorganic gels (plugging ratio of 77.2%) or organic gels (84.8%), the composite gel system has a plugging ratio of up to 99.5% using a core with water permeability of 4300 mD. Besides, the reservoir applicability of the composite gel was studied, and the results suggested that the composite gel system had good resistance to dilution, mechanical shear, oil corrosion, and aging and could be quickly removed after plugging.

N2 Foam Flooding Combined with Gel Plugging for Enhanced Oil Recovery in High-Temperature Reservoirs: Laboratory Experiments and Numerical Simulations

“…The starch graft gel system is the in situ cross-linked polymer gels. The injected gelling solution could be easily pumped into target zones and penetrate into pores and throats to ensure sufficiently deep placement . In the gel plugging experiment, the viscosity of modified starch graft gel solution was 18.15 mPa·s at 105 °C and it was easy to inject into the cores.…”

“…The injected gelling solution could be easily pumped into target zones and penetrate into pores and throats to ensure sufficiently deep placement. 49 In the gel plugging experiment, the viscosity of modified starch graft gel solution was 18.15 mPa·s at 105 °C and it was easy to inject into the cores. After the aging period, the 3D network structures were formed in porous media and the maximum viscosity of the gel could be 34950.92 mPa·s, which could act as plugging agents.…”

Preparation of Low-Viscosity Epoxy Resin Sealing Agent and Evaluation of Injection, Plugging, and Degradation Properties

“…However, with the continuous advancement of field execution, it was believed that the plugging agent was critical, and its comprehensive performance plays a crucial role in the application process . Nowadays, the commonly used plugging materials, such as inorganic gels, organic gels, and cement, for external sealing of horizontal well casing channeling, casing damage repair of oil and gas wells, and sealing the high moisture content well during the construction of the repeated fracturing had the following problems: − (1) The conventional plugging agent was diluted easily by oil or formation water to induce the ineffectiveness of water plugging. (2) The driven water readily broke through the sealing zone for the low adhesion strength agent and the surface layer of casing pipes, cement sheaths, and rocks.…”

Enhanced Oil Recovery Mechanism and Technical Boundary of Gel Foam Profile Control System for Heterogeneous Reservoirs in Changqing

“…Gel and foam systems, as the two most widely used plugging agents, have achieved positive progress in both laboratory experiments and field applications in recent decades [ 4 , 5 ]. Gel-based plugging systems have been used on a large scale in the 1990s, and various modified gels, micro-nano microspheres, polyethylene glycol gels (PEG), and chitosan-based gels have been developed, including preformed particle gel (PPG) and HPAM weak gels with various particle sizes and compositions [ 6 , 7 , 8 , 9 , 10 ].…”