Performance Evaluation and Application of the Non-Clay Weak Gel Drilling Fluid for Daniudi Gas Field

Daniudi Gas Field reservoir has low degree of porosity and permeability, thus it is highly susceptible to the invasion of the solid phase of clay particles in the drilling fluid during the drilling process, in view of these problems, we introduce the non-clay weak gel drilling fluid system. Experiments of the drilling fluid system for rheological property, salt-resisting pollution, hot rolling rate of recovery, reservoir damage evaluation and drilling fluid treating chemical opimization have been taken. The experimental results show that the drilling fluid system has excellent temperature-resisting and salt-resisting character, good ability of suspending debris and strong inhibitory action, its rheological property can meet the needs of the long horizontal section of drilling engineering and the reservoir protection effect is excellent. In DP21 well horizontal section construction, each performance indicator of the drilling fluid can be controlled well and effectively solve the problems of cuttings carrying, borehole wall stability and reservoir protection, successfully completed the DP21 well drilling construction task.