Research And Application Of Complex Formation Geological Drilling Fluid

This paper studies on the organical modified bentonite drilling fluid materials, amylum graft copolymerization drilling fluid materials and swelling-type drilling plugging material. Acrylic acid and acrylamide asintercalation as agent, organical modified bentonite drilling fluid materials were prepared by pressure mixing method. The layered structure of bentonite was characterized by XRD, FT-IR, SEM. The results show that the organic groups go into the structure of the layer of bentonite or bonded graft. Drilling fluid performance test results shows that, compared with the sodium bentonite drilling fluid materials, fluid filtration and lubrication coefficient of organic bentonite drilling decrease. Field tests shows that its ability of carrying the rock powder and inhibiting the drill pipe wall fouling is great. Amylum graft copolymerization drilling fluid materials were prepared by graft copolymerization. The viscosity and fluid loss of Amylum graft copolymerization drilling fluid have a better performance, reducing rate of the relative expansion can reach 61%. Field tests show that it is a kind of good drilling in fresh water, 4% brine and saturated brine fluid materials. A swelling-type drilling plugging material was prepared. Drilling fluid performance tests and field tests results show that the swelling type of plugging material is better than any other.Study on design of complex formation drilling fluid system was carried out. We summerized how to choose the type of drilling fluid, determine the performance parameters of drilling fluid, optimize drilling fluid, estimate the amount of drilling materials, design drilling mud solids, control measures and the daily maintenance programs.LMB-GLA drilling system, grafted amylum-GLA drilling system and grafted amylum copolymerization drilling system which were used in complex formation have been studied. Field experiments shows that LMB-GLA drilling system have made a good performance to stabilize hole wall. The formation cracks of fracture zone can be blocked effectively, improving ground bearing capacity. The density and viscosity of fluid must be increased in the fracture zone where is easy to block out, to ensure that the debris levitation force and support of fluid . LMB-GLA drilling system with good rheological properties can satisfy the requirements of the rope core drilling. Grafted amylum-GLA drilling system can protect wall, stabilize the hole wall, carry the rock powder. Normal drilling footage per day was 30 to 45 meters, and the drill pipe wall did not bear clay skin. Grafted amylum copolymerization has a good performance in protect wall, good rheological and thixotropy properties. Its preparation method is simple and it easy to used. The material of the drilling system is easier to disperse, the slurry process was completed only 30 to 40 minutes. Other drilling system also have a good performance.