DEVELOPMENT METHOD OF OIL DEPOSIT WITH HORIZONTAL WELLS Russian patent published in 2011 - IPC E21B43/20 

FIELD: oil and gas industry.

SUBSTANCE: method involves drilling in the well of the main transport horizontal shaft in productive formation; drilling from the main transport horizontal shaft of additional branched uprising shafts to working sections of formation and operation of well during oil extraction. According to invention, the main transport horizontal shaft is drilled above oil-water contact - OWC. Prior to drilling of uprising shafts which are drilled in roof of productive formation, to the main transport horizontal shaft there pumped is water isolating compound in the volume allowing to obtain water-isolating shield around the main horizontal shaft with diametre of not less than 0.5 m. At that, as water-isolating compound there pumped is water suspension of polyacrylamide cement solution or consisting of bridging composition consisting of water solution of biopolymer and reagent including sodium silicate. At that, bridging composition and chemical structuring initiator additionally pumped after it and representing 20-35% water solution of calcium chloride is pumped depending on the formation intake rate in several alternating portions 2-10 m³ each, which are separated with water buffer in the volume which excludes mixing of portions during pumping process. At that, as sodium silicate in bridging composition there used is sodium liquid glass mixed with water solution of biopolymer, consisting of 0.2-0.5 wt % xanthane biopolymer and 0.03-0.3 wt % bactericide in the ratio of 0.8:1 to 1.4:1.

EFFECT: method is simplified and its efficiency is improved at the same time owing to reducing water blockage of extracted products.

1 dwg