Preparation and Applications of an Advanced Lubricant for Brine Water Based Drilling Fluids

Brine water based drilling fluids have advantages on protecting reservoir and stabilizing well hole, meanwhile, it also have some defects such as low lubricity and strong corrosivity, especially the low lubricity have already become an important problem demanding prompt solution.Focusing on the problem, a new lubricant named BLC that suit for brine water based drilling fluids were prepared.As the basic material of BLC, a recycled animal and vegetable oil REO was made in to a special intermediate product SPP-REO that have good lubricity, heat resistance and salt resistance by using three steps of chemical modifications.Salt tolerance lubricants BLC-1(suit for summer) and BLC-2(suit for winter) were obtained by mixture of SPP-REO and other auxiliary materials.With 0.6% BLC-1, the △ Kf (reduction rate of sticking coefficient) of a special silica brine drilling fluid of Gang 308-2 Well reached more than 50%; with 0.5% BLC-1, the △ Kf of polymer drilling fluid of Zhong 3-56 Well reached 64%; with 0.5% BLC-2, the △ Kf of organic salt drilling fluid of Baiku-H1 Well reached more than 30%; With 0.6% BLC-2, the △ Kf of silica drilling fluid of Fang 15-16 Well reached 59%; with 0.5% BLC-2, the △ Kf of polymer drilling fluid of Xi 48-21 Well reached 59%.BLC lubricant obtained good performances when it was used by CNPC Bohai Drilling Engineering Ltd. in Dagang Oilfield.