Abstract

The paper sets forth some major aspects of the bottom-hole formation zone treatment with the use of monofuel thermolysis.

The bottom-hole formation zone treatment using monofuel (MF) thermolysis refers to thermal and gas chemical enhanced oil recovery. It is an effective combination of heat and chemical monofuel combustion products; their integrated effect results in the following:

  • improvement of lithological bottom-hole formation properties as a result of heat treatment and creation of pressure impulse attributing to the removal of asphaltic tar paraffin depositions (ATPD) and fracture formation.

  • oil viscosity decrease resulted from heat effect and monofuel thermolysis products;

  • lowering of surface tension at the interface of displaced and displacing fluids and improvement of rock surface wettability.

  • decomposition of chemical agents under the temperature effect producing gases and other substances which increase displacement efficiency;

  • formation of water-, gas-and-oil emulsions and foam systems in highly permeable zones resulting in leveling the displacement front and increasing involvement of heterogenous formations into the oil recovery process.

Principally MF represents the solution of combustion agents and oxidants according to the general pattern: “oxidant + combustion agent + solvent”.

The MF advantage is the following: it requires no solution related to propotional dosage and allows control of heat and gas effects by simple methods. In addition it considerably increases allowables for oil formation depths to be treated due to the possible injection of liquid monofuel by high pressure pumps. The injection pattern is single flow. It reduces accessories, and the number and range of the equipment used.

As a monofuel the technology uses water solution of cosoluted nitrogen containing compounds, one of which if fuel, the other - oxidant.

MF decomposition in the fluid is a number of redox reactions yielding the following end products: Water H2O-steam, nitrogen N2, carbon dioxide CO2 and ammonia NH3.

Water is the solvent and reaction product. It changes to steam in the process temperature conditions. The change consumes some energy produced in MF thermal decomposition and oxidation.

You can access this article if you purchase or spend a download.