TECHNIQUE TO DEVELOP OIL FIELD AT LATEST STAGE Russian patent published in 2004 - IPC

FIELD: oil and gas industry, development of multihorizon oil deposits. SUBSTANCE: invention envisages drilling of injection and producing wells, injection of displacing liquid into injection well and extraction of pool product through producing well. In process of drilling first open productive formation in section of clay in field which is subjected to crumbling and swelling is examined by geophysical method for profitability. Then drilled out part of well is secured by sinking of production string. Thereafter drilling is continued with bit of smaller diameter and next productive formation is drilled in by drilling fluid under balance or differential pressure in order to preserve collector properties of formation. Geophysical control is conducted in process of drilling below sunk production string to evaluate profitability of formations. Decision on need for termination or continuation of further sinking is made by results of mud logging and analysis of slurry. If formation is profitable it is developed by open face till full exhaustion. Later the rest of underlying formations are open and developed according to similar scheme. If walls of productive formations are susceptible to crumbling they are overlapped by tailings from material drilled easily, for instance, aluminum or glass reinforced plastic. When two adjacent formations are uniform by permeability and are made of hard rocks they are developed by open face. EFFECT: diminished contamination of productive formation, its flooding and wear-out of production string. 3 cl, 1 dwg