Research and Application of Flexible and Latex-cement Slurry in Shale-gas Horizontal Well Cementing Operation

Long horizontal and extended reach well drilling was the key technology to improve the efficiency of the shale gas development and production.During well drilling because the well was shallow,and the horizontal section was long,the cementing quality was often difficult to be guaranteed.To improve the quality of shale gas horizontal well cementing,a set of flexible and latex-cement slurry systems were developed.The performance of slurry systems were evaluated in laboratory.The result indicated that this cement system not only had good stability and the free-water control ability,also had rapid development speed of static gelling strength and stronger ability of fluid blocking,and a stronger anti-channeling effect.In addition,simulation perforation test showed that it had higher impact toughness,which has important significance to ensure the integrity of the cement sheath in perforated completion.This cement system is used in long horizontal and production casing cementing of Well Janye 2with cemented horizontal section of 1050 m.Variable density logging after 48 hshows that the cementing quality of Well Janye 2is very well.