Homogeneous Steam Injection Technology In Horizontal Wells

As of Dec. 2008, Liaohe Oilfield completed 706 horizontal wells, including 670 heavy oil horizontal wells. All the heavy oil horizontal wells drilled were completed by screen casing, using method of general steam injection. As the existence of difference of physical property in horizontal section, or by the extend of exploitation, creating a local conning of steam, and uneven employing in horizontal section. Through the analysis of temperature test data of more than 260 horizontal wells drilled in 2006, the number of uneven employing horizontal wells is about 80% of the total number of wells, the sections employed well in single well account for about 1 / 3 to 1 / 2 of the total sections .In order to enhance horizontal well reserves'producing degree and ease horizontal hole section reservoir's producing disproportionation problem, we launch homogeneous steam injection technology in horizontal wells research work. The technology is composed of dual string steam injection technology in horizontal well and sectional steam injection technology in horizontal well. Dual String Steam Injection Technology is the technology which running the 1.9"integral joint tubing into 4 1/2"vacuum heat insulated tubing string (ID is 76mm). Realizing selective inject to A point (heel) and B point (toe) by minor annulus and 1.9"integral joint tubing, it is able to dynamic regulate two-point's steaming proportion at the well head. Sectional steam injection technology in horizontal well designs couple steaming valves in long horizontal hole section through the analyze of physical property condition at the bottom of the well. In the process of steam injection, steaming valves will affect the whole horizontal hole section at the same time. Bore diameter size of the steaming valves is calculated by design software.The technology has formed two original technology, and an utility model patent license.In addition, three patents and one utility model patent has been declared, and 2 enterprise standard formed. The technology gained the first level innovation prize of Liaohe Oilfield Company in 2008.Since 2006, as 2010 , the technology has been implemented on-site in234 wells, of which is the 91 two-pipe steam injection wells, 143 sectional steam injection wells. The technology achieved good results through field tests,increasing oil production by 9.0×104t totally, Achieving Benefits 144 million, of which two-pipe steam injection by oil production 60426t, sectional steam injection by increasing oil 29511t.