Environment-friendly low-molecular-weight branched polyether ammonia shale intercalation inhibitor

Abstract

The invention provides application of environment-friendly low-molecular-weight branched polyether amine as a shale intercalation inhibitor, belonging to the technical field of oil and gas field drilling. The low-molecular-weight polyether amine is synthesized from ester compounds with amino groups and ether bonds and ether compounds containing olefinic bonds through a one-pot synthesis method ora step-by-step synthesis method. The shale intercalation inhibitor prepared from the low-molecular-weight branched polyether ammonia is prepared by mixing the low-molecular-weight branched polyether ammonia and water, wherein the mass ratio of the low-molecular-weight branched polyether ammonia in the shale intercalation inhibitor is 0.5%-3%. The shale intercalation inhibitor prepared from the low-molecular-weight branched polyether amine provided by the invention has good biodegradability, is safe and non-toxic, and has obviously improved inhibition performance compared with similar intercalation inhibitors, the raw materials are easy to obtain and low in price, and the provided synthesis method is stable and reliable and is suitable for industrial production.

Description

technical field [0001] The invention relates to the technical field of oil and gas field drilling, in particular to a low molecular weight branched polyether ammonia shale intercalation inhibitor. Background technique [0002] Borehole wall instability has always been a worldwide problem that needs to be overcome in the drilling process. It often leads to complex accidents such as well wall collapse, diameter shrinkage, and pipe sticking, which increases drilling time and drilling costs. According to statistics, 75% of wellbore instability problems mainly occur in shale formations, especially water-sensitive formations. Shale formations have high clay mineral content, shale gas horizontal wells have long horizontal sections, and drilling fluids are in contact with formations. If the time is long, the shale hydration will be more serious, and the wellbore instability will be more prominent. Although oil-based drilling fluid has the advantages of high temperature resistance,...

AI Technical Summary

Problems solved by technology

[0004] Most of the polyamine inhibitors studied and applied at present have a linear structure. For linear polyamine inhibitors, they usually have an irregular linear configuration after being dissolved in water. When they are used in the shale gas drilling process , the entanglement and coating on the clay are uneven, which is easy to cause repeated adsorption or no adsorption

At the same time, the active groups generally exist at both ends of the molecular chain, so that a molecular chain usually only contains two active groups. In this case, the effect of linear polyether ammonia inhibitors often has certain limitations. , and the high molecular weight polyamine compound is difficult to enter the clay layer, so that its inhibitory performance is limited

Images