Study On The Microstructure Of Bonding Interface And Reinforcement Mechanism Of Interfacial Bonding Strength

Now many domestic oil fields have come into later exploitation stage. Exploiting intensity continues increasing. The circumstances under oil wells have been much more complex than ever. Requests on resistance of erosion destructibility of sealing interfaces that related to sealing up and cementing exercises in petroleum engineering are more and more of rigidity. It is urgently needs to resolve all sorts of problems that affect interface bonding quality, especially the problem that how to establish and hold the interface bonding strength on conditions of fluid seeping. It is significance for resolving the correlative technical staggering problems to develop researches on microstructures of cementation interface.This article firstly establish dynamic curing experiment means and measurement that can simulate the temperature, pressure and fluid seeping conditions. Base on the researching means and achievements of bonding interface microstructures of cement-based compound materials, with the applications of the modern theory of microstructures on bonding interface of cement-based compound materials, put emphasis on the research of the microstructure andmechanical behavior of the bonding interfaces between three gel materials: oil well cement, YLD-1 plugging agent, YLZ-1 temporary plugging agent, and steel pipe, drilling cores soaking with mud fluids. Base on these, establishing relative microstructure models, presenting enhancement mechanism of bonding strength on interface from new point of view, presenting the ways that can resolve the problems of preventing and resisting the oil and gas permeation on the bi-interfaces on well cementation and oil and water wells plugging, and the ways how to extend the sealing period of validity.The primary research achievements of this article are:1. Demonstrating the basic conclusions of classic microstructures research on bonding interfaces of cement-based compound materials through experiments. That is, there is a transition zone on the bonding interface, which is a bottleneck of the performance of permeation resisting of plugging agent. It is more conspicuous under dynamic curing conditions.2. Establishing 6 primary bonding interface microstructure models, revealing the mechanism why the cement mantle in well cementation is out of work and the mechanism how the YLD-1 bridging particle increase the bonding strength on interface, thereby, presents the enhanced microstructure models on the bonding interface and the mechanism of reinforced bonding strength on interface.3. Through the experiments it is found that under dynamic curing conditions, the key factors that affect the bonding strength on interface of plugging materials are: the compositions and property of the hydration productions on interface transition zone, the bond regeneration mechanism how the solidification products of the plugging materials on bonding interface self-rebuild.4. Presenting the point of view to build the cementing fluid systems of polyphase oil well cement-based compound materials, at the same time presenting series supporting technologies which can settle the problem of bonding quality on bi-interface in well cementation. Providing theoretical guide for resolving the problems of permeation resisting strength of the cement mantle in well cementation from the integral and systemic point of view, and for building new cementing fluid systems which mechanism of action are completely contrasting with conventional method.5. Presenting methods of strengthening bonding strength on interface, on these grounds designing and researching new type of plugging agent YLD-1 for oil and water well. Field experiments show that this new bridging particle can improveconstructing period of validity obviously, which prove that the textual theoretical investigating achievement has certain guiding significance for field works.