Sand and gravel concrete slurry used for plugging and its plugging method

Abstract

The invention discloses dinas coagulated mortar for leaking stoppage and a leak stopping method thereof. The dinas coagulated mortar for leaking stoppage comprises the components which are directly mixed by weight percentage as follows: 45-50% of peastone, 10-15% of hill sand, 25-30% of cement, 6-10% of coal ash, 0.6-0.8% of drag reducer (smk) and 4-6% of water. According to the invention, the filling effect of a cement mortar system is improved, the mobility is reduced, and the strength of the blocking layer is enhanced by way of mixing dinas in different granularities in the cement mortar system, so that dinas coagulated mortar is effectively retained in the leaking layer, and coagulated with ground cement and dinas, therefore, the strength of the leaking layer of a fragmentized crack is improved, and the leaking stoppage success rate at one time is improved.

Description

technical field [0001] The invention relates to the technical field of petroleum drilling, in particular to a sandstone concrete slurry for plugging and a plugging method thereof, which are suitable for vicious leaks that occur when vertical fracture fracture zones are encountered. Background technique [0002] The buried depth of the Jurassic Luohe Formation in Changqing Xifeng Oilfield is 700-1200m, and the vertical and horizontal fractures are well developed, which is prone to return loss. In some areas, there are vertical fracture fracture zones in the Luohe formation, generally 1-5 meters in length , the main feature is that when the vertical fracture fracture zone is drilled, the drill bit cannot be pressurized, and there is also a phenomenon that the drill bit cannot be pressurized in multiple sections. For this type of well, conventional bridge plugging and cement slurry plugging are basically ineffective, and it takes a lot of work. Gravel filling combined with grou...

AI Technical Summary

Problems solved by technology

[0003] 1. It is difficult for conventional plugging materials to enter the leakage layer to form retention and fill. Currently used plugging materials such as bridge plugging materials, stone powder, cement, etc. are difficult to stay in the fracture zone. well almost ineffective

[0004] 2. Existing plugging materials cannot take care of both filling and cementation at the same time, and are easy to flow away with open formation loss channels. Conventional plugging materials such as bridge plugging materials, stone powder, etc. only have filling capacity (and the filling capacity is limited) and have no cementing capacity. The materials are easy to flow and be scoured with the gaps between each other, and cannot stay for a long time; although the cement-based plugging materials can be cemented, they cannot form a filling, and they tend to flow to the far end of the leaky layer in the continuous channel of the leaky layer, failing to achieve plugging the goal of

[0005] 3. After filling the gravel, there is a defect in the plugging process of cement injection. At present, materials such as gravel and stone powder are more effective in filling the cracks than cracks; however, it is difficult to control the particle size of materials filled into the leaking layer of the crack. There are no leakage layers, and the small ones cannot be retained. In actual construction, there are often two situations. One is that there is no cement plug in the wellbore after cement injection, and the cement slurry will wash away the gravel in the cracks. All of them are plugged in the wellbore, and the large-sized gravel cannot enter the fracture, and all the cement slurry is retained in the wellbore