Problems and measurements of sliding sleeve staged fracturing completionin casing cementing horizontal wells

The low permeability difficult-to-produce reserves and unconventional oil and gas reserve in Dagang oilfield is rich, and horizontal wells with staged fracturing completion technology is probably the mainly mean to economically and efficiently develop these reserves. In order to analyze the applicability of staged fracturing in horizontal well completion technology in Dagang oilfield, application trials of openhole packer staged fracturing completion, casing cementing sliding sleeve staged fracturing completion technology and hydraulic jet perforation completion with immovable string were conducted to form a new well completion technique, which take the casing cementing and sliding sleeve subsection fracturing as the main technology. The newly process has the advantages of integrated pipe column for well cementing, completion and staged fracturing, full size and fracturing operation continuous, which can shorten the working period and sliding sleeve can be closed for water blocking point in late water-producing layer. Meantime, there also presents some problems with this technique such as wellbore production plug caused by ball dropping, poor cementing quality because of rubber plug no pressure and adjacent wells connection. Aiming at the existing problems, analysis and evaluation were conducted, and solutions were proposed in this paper. Field application primarily realized normal production of oil wells, which provides foundation for the further scale application of the similar staged fracturing completion technology.