Blocking technology with bridge plugs for heavy oil thermal recovery on 139.7mm casing wells

The heavy oil reservoirs of Henan oilfield are such small complex fault blocks in shallow thin beds that their water and oil relationships are complex. As a result, there are troubles such as early water breakthrough, quick increasing water-cut and fast edge water incursion in the thermal recovery on slim-hole heavy oil well. To provide a novel blocking approach for the downhole high-temperature water resulting from these problems, a blocking technology with bridge plugs is developed. Firstly, two sets of assemblies with bridge plugs for the blocking technology are presented. Secondly, characteristics, structures, and operating principles of the key parts of the two assemblies such as the release sub and the novel bridge plug which is integrated with functions of releasing, seating, setting, unsetting are described. Lastly, field applications verified the feasibility of this blocking technology with bridge plugs. The results show that the development of this blocking technology with bridge plugs might provide sound support for economic and effective heavy oil recovery in low-grade reservoirs.