What are the relevant definitions and prevention methods of lost circulation?

Classification:

Industry dynamics

Release time:

2020-07-28

【Summary Description】 Well leakage is actually the phenomenon of drilling fluid and cement leaking into the bottom layer. Well loss is a very common but particularly serious accident in drilling work, because it can lead to borehole collapse. Therefore, we must find problems in advance and deal with them quickly and effectively in order to avoid more serious situations.

钻杆Well leakageIn fact, it is the phenomenon of drilling fluid and cement leaking into the bottom layer. Well loss is a very common but particularly serious accident in drilling work, because it can lead to borehole collapse. Therefore, we must find problems in advance and deal with them quickly and effectively in order to avoid more serious situations.
The reason for the occurrence of lost circulation is very simple, that is, the pressure in the well is greater than the formation fracture pressure. In practice, we will find that lost circulation often occurs in loose strata, cracked strata or caves.
1. If it is a slight mud loss, then we only need to adjust the performance of the drilling fluid, reduce the pressure difference and plug the gap in the rock formation, and then we can drill normally.
2. In case of fractured leakage in the oil and gas layer, the fracture can be blocked by injecting lime milk drilling fluid.
3. The most serious is the cavern type leakage. We usually take directly from the wellhead into the stone mud ball filling, or injection of cement plugging.
DrillingWell leakageThe main indication on the site is that the amount of fluid returned from the drilling wellhead is less than the amount pumped in. In severe cases, mud may not be returned to the wellhead at all. After leakage occurs, different methods shall be adopted on the site according to the situation of leakage. For wells with complex downhole pressure system and formation, the method of plugging can only be adopted; while for wells with single downhole pressure system and strong formation structure, the method of reducing drilling fluid density can be adopted. In general, the prevention of well leakage shall be taken as the priority to avoid well leakage due to human error.
Therefore, before drilling, the possible leakage of the well will be eliminated as much as possible, and the data will be collected. All work that can prevent well leakage should be done in advance as far as possible.
Well leakage will cause the drilling work to stop or interrupt, seriousleakageIt will delay a long production time and cost a lot of manpower, material and financial resources. If the drilling leakage is not treated in time, it will also lead to drilling well collapse, blowout and sticking accidents. Therefore, prevention and timely treatment of well leakage is a very important work in the drilling process.






Key words:

weilida drill