Research On The Completion Technology Of Multi-branch Wells

Liaohe oil field began the multil-branch well research in 1999. The research on joint mechanical integrality, joint hydraulic integrality and cement slurry system has been done successfully. The DF-1 multilateral well completion system has been developed. The technology keeps ahead in China.The connect assembly between main wellbore and subside wellbore was tested on the ground in order to prove the mechanical strength and hydraulic pressure seal of Liaohe DF-1 multi-branch well completion system. Some improvement design was done about casing direction equipment, hollow incline facility, incline basement, multi-branch casing tool according to the ground test. The main wellbore hanging system assembly was improved in order to torque and stress need. The support and hanging system is reliable. The top improvement on the hollow incline facility ensures the multi-branch well completion pipe enter the wellbore and the main wellbore is connected with the subside wellbore. There are some magnitude technology breakthroughs about the heavy drop on the incline facility and casing rotating directional orientation. The tool of integrated multi-branch well cementing pipe string can support pull or stress 70-90 tons load and assure accurate hanging and accurate coincidence between casing orientation and hollow incline facility. In addition, the multi-branch well cement problem was analysed. The slurry system was selected and the slurry prescription was studied. The casing assembly was improved and a well completion tool was developed.The spot tests have been done in Jin 612-12-Xin-22FP multi-branch horizontal well and Gao-3-4-17 well by using the multi-branch well technology. The spot tests have proved that the joint mechanical integrality, mechanical support strength, welldown connectivity and window seal technology between main wellbore and subside wellbore have improved very well. The tests gain the desired result and prove that the improved Liaohe DF-1 multi-branch well completion system is reliable and advanced.