Carbonatite oil well density selectivity water shutoff agent and preparation process thereof

Abstract

A carbonatite oil well density selectivity water shutoff agent comprises, by weight, 100 parts of cement, 60-75 parts of coal ash, 50-58 parts of clay, 52-62 parts of micro silicon, 5-8 parts of early strength agents, 16-28 parts of fluid loss agents and 1100-1200 parts of water. A preparation process of the carbonatite oil well density selectivity water shutoff agent includes: weighing the fluid loss agents and the early strength agents according to the formula ratio, dissolving the weighed fluid loss agents and the weighed early strength agents into the water obtained according to the formula ratio, and then adding the cement, the coal ash, the clay and the micro silicon according to the formula ratio so as to obtain the carbonatite oil well density selectivity water shutoff agent. The carbonatite oil well density selectivity water shutoff agent has the advantages of capability of staying among oil-water interfaces to set up a water shutoff partition, guarantee of solidification effects, safety in injection, expansion of shutoff radius, high compression strength after solidification, easiness to prepare, good injection performance, simplicity in construction process and high construction efficiency.

Description

technical field [0001] The invention relates to an oil well water shutoff agent, in particular to components and a preparation process of the carbonate rock oil well water shutoff agent. Background technique [0002] Carbonate storage spaces are mainly karst fractures or caves, controlled by high-angle fracture zones and the development of karst pores and caves along the fractures, the reservoirs vary greatly in vertical and horizontal directions, and have strong heterogeneity. At the same time, there is a large bottom water body. During the production process, once the bottom water breaks through and enters the reservoir, the water cut of the oil well rises rapidly, resulting in a sharp drop in production. At present, the polymer jelly, conventional cement, and precipitation water shutoff agent used in the oil field water shutoff agent will degrade under the formation conditions of high carbonate temperature and high salt, and the solution viscosity is large. The pumping ...

AI Technical Summary

Problems solved by technology

During the production process, once the bottom water breaks through and enters the reservoir, the water cut of the oil well rises rapidly, resulting in a sharp drop in production

At present, the polymer jelly, conventional cement, and precipitation water shutoff agent used in the oil field water shutoff agent will degrade under the formation conditions of high carbonate temperature and high salt, and the solution viscosity is large. The pump injection resistance is large, which can easily block pipelines and other equipment; conventional cement is easy to leak and pollute the production layer, and the water blocking radius is small, and the effective water blocking range is small; the precipitation type water blocking agent has low strength and is not resistant to erosion

Therefore, the current conventional water plugging technology is not suitable for carbonate oil wells with high temperature and high salinity