DEVELOPMENT METHOD OF OIL DEPOSITS WITH HORIZONTAL WELLS Russian patent published in 2013 - IPC E21B43/20 

FIELD: oil and gas industry.

SUBSTANCE: method involves drilling of a horizontal well with a descending working face to the formation bottom, injection of displacement agent and extraction of the product. According to the invention, investigation of the well is performed, level of oil-water contact (OWC) is determined; after that, an ascending shaft to the formation roof is drilled out of the horizontal well at the distance of 150-500 m from the descending section. Secondary drilling of the formation is performed below OWC level in the descending section and above OWC level in the ascending shaft. The ascending shaft between the horizontal wall and the opening is equipped with a packer with a valve passing the product of the formation to the horizontal well, and the horizontal well between the descending section and the ascending shaft is equipped with an additional packer with a spring-loaded valve passing the liquid from the horizontal shaft to the opening of the descending section at the pressure exceeding hydrostatic pressure in the well. After that, a pump is lowered on tubing to the well, by means of which the product of the formation is extracted from the ascending shaft above OWC level. At reduction of formation pressure the pump recovery of the formation product is stopped, and displacement agent is pumped via inter-tube space through the descending section and the spring-loaded valve of the additional packer to the formation below OWC level to maintain formation pressure. Then pumping is stopped, and the pump recovery of the product is continued. When necessary, pumping cycles of displacement agent are repeated.

EFFECT: improving coverage efficiency of formations by production as to surface area and as to the section, well flow rates, additional oil recovery, improving oil recovery of formations and maintaining optimum formation pressure.

2 cl, 1 ex, 1 dwg