The practice of new oil and gas field development often shows that the real oildrainage boundary is larger than supposed one. On account of this the special zones are fixed in the area of oil field that are not in the area of drainage usually. The similar situation is considered by the example of oil field in Western Siberia. It was suggested to develop the area of field that was not covered with well spacing by means of construction of two lateral branches with horizontal sections instead of four deviated wells to solve this problem. The drilling technology of lateral branches and technology of tailing-in are considered by stages. A review of equipment that is used in drilling of lateral branches and in completion of wells with branch holes is given. The economical expediency of project realization of lateral branches construction.
