High efficient plugging agent for well drilling

Abstract

The invention relates to a plugging agent during well drilling in oil and gas field, and particularly to a high efficient plugging agent for severe lost circulation. The components are, by weight: 18-25% of walnut shell powder, 8-10% of sawdust, 8-10% of cottonseeds, 10-15% of hull powder, 20-30% of active plugging agents, and 15-25% of elastic rubber granules, and the raw materials are mixed uniformly to obtain a high efficient plugging agent for well drilling. According to the invention, the fibrous plugging agent with granules is formed by mixing natural plant inert materials, a synergistic agent, and a reinforcing agent with a certain preparation ratio. The plugging agent of the invention has the advantages of wide covering area for leak stopping, high pressure bearing capacity, good plugging effect, high success rate for disposable leak stopping, simple on-site preparation process, and reliable and safe construction, which can achieve the purposes of reducing loss of lost circulation and saving comprehensive cost. The high efficient plugging agent of the invention is applicable to leak stopping operations under various lost circulation conditions with good leak stopping effect and high success rate, and is superior to other types of plugging agents.

Description

technical field [0001] The invention relates to a lost circulation agent in the drilling process of oil and gas fields, in particular to a highly efficient lost circulation agent for vicious lost circulation. Background technique [0002] Lost circulation is one of the factors that have the greatest impact on drilling speed and drilling cost in various complex situations, and it is a difficult problem that plagues oil and gas drilling. Once lost circulation occurs, it not only needs to consume a large amount of drilling fluid materials and plugging materials, but also prolongs the engineering time, increases the cost of development, and even causes downhole accidents such as stuck drill, buried drill and scrapped the whole well. At present, there are many plugging agents with different characteristics in the domestic market, some of which are plant fiber plugging agents mainly composed of cotton fibers, peanut shells, walnut shells and other plant fibers; some are mainly com...

AI Technical Summary

Problems solved by technology

When directly using plant fibers such as cottonseed hulls for plugging, due to the inherent characteristics of these fibers: too light specific gravity, difficult to control size, easy to knot, poor fluidity and other factors, the plugging effect is poor during use and the pressure bearing capacity is weak; while particles or The plugging ability of powdery plugging agent for large cracks is limited; when using bridging plugging agent, there are phenomena of "door sealing" (the plugging agent cannot enter the leaky layer) and "regurgitation" (leakage after plugging)