The practice of new oil and gas fields development often shows that the real oil-drainage boundary is larger than the assumed one. In this connection special zones are fixed on the territory of oil field, which usually are not included into the drainage zone. Such situation is considered on the example of an oil field in Western Siberia. To solve this problem, it was proposed to develop the area of the field not covered by wells by constructing two lateral branches with horizontal sections instead of four inclined wells. The technology of drilling the lateral branches and the technology of tailings cutting are discussed step by step. A review of the equipment used in drilling lateral branches and completing branch wells is given. The economic feasibility of the lateral branch construction project is considered.
