COMPOSITION BASED ON A CROSSLINK POLYMER SYSTEM FOR LIMITING WATER INFLOW IN PRODUCTION WELLS AND LEVELING THE INJECTIVITY PROFILE IN INJECTION WELLS Russian patent published in 2023 - IPC C09K8/508 E21B33/138 

FIELD: oil production.

SUBSTANCE: compositions used in carrying out measures to limit water inflow in production wells and to equalize the conformance control in injectors. The composition contains 3-10 wt.% of a cross linker in the form of potassium dichromate or sodium dichromate, 0.01-10 wt.% of the pour point time regulator, 0.01-5 wt.% of the rheological properties regulator, 0.01-15 wt.% bridging agent and water. At the same time, the rheological properties regulator includes a modified wood processing product based on cellulose ethers, or a product based on modified xanthan gum, or polyacrylamide. A surfactant based on aminoalcohol derivatives with a content of ethoxylated amines of at least 2 vol.% is used as a pour point time regulator. Polypropylene fibers or calcium carbonate are used as bridging agents. Moreover, the composition additionally contains 3-40 wt.% of the polymer in the form of a sulfite-modified phenylpropane polymer with a molecular weight of more than 35,000 amu. In addition, the composition additionally contains 0.01-5 wt.% of the crosslink activator, which is used as etidronic acid or an acid reagent containing citric and oxalic acids in a ratio of 1:1-3, respectively.

EFFECT: increase in penetration due to the possibility of regulating pour point time of the proposed composition in a wide temperature range (up to 300°C) while maintaining the strength and stability of the formed gel, as well as ensuring the versatility of the composition due to the possibility of using it in terrigenous (porous) and carbonate (fractured) formations.

1 cl, 2 tbl