Aquifer. What is it? Signs of an aquifer? How to find, identify an aquifer when drilling a well? Hello to viewers and subscribers of my channel. Today I will tell you about the aquifer, what it is and how to identify an aquifer, what are the signs of an aquifer. An aquifer is a zone of saturation with groundwater. It is usually expressed in sand or fractured limestone, granite sandstone. We are engaged in drilling wells for sand, so I will talk more about the sand aquifer. One of the main indicators of an aquifer is the absorption of the drilling fluid. Since the static water level in the well is usually below ground level. Moreover, the stronger the absorption of the drilling fluid, the greater the well flow rate will usually be. It is also very important to pay attention to what kind of rock is washed out with the drilling fluid. If the aquifer is expressed in sand, then sand will be washed out. Moreover, the larger the sand particles, the greater the well flow rate will be. It is also worth paying attention to the roundness of the particles. If you see large particles of angular, unrounded shape, then most likely these are loams and there is very little water in them, if any. As they say, water wears away stone. Another important indicator is the rate of penetration, the speed of drilling a well. The rate of penetration in sand, as a rule, will be faster than in clays and loams. It would seem that everything is simple. And there should be no problems with determining the aquifer. But these signs do not always work simultaneously. It happens that there is absorption, but the rate of penetration has not changed. Or the rate of penetration has increased, but there is no absorption of the drilling fluid. The fact is that these are superficial signs of an aquifer. There may be no absorption when static at ground level or close to ground level. It may also not be there due to the high density of the drilling fluid. The rate of penetration may not change, and may even slow down even if it is an aquifer. In most cases, it is quite possible to determine the presence or absence of an aquifer by such signs. But not always. Moreover, the drillers themselves will never know that they have "missed" an aquifer. This is exactly what happened when we first encountered logging. Evgeniy Babin, who is often present in the videos on my channel, made a gamma logging of an already drilled well on a neighboring site from my client's site and suggested drilling an Abyssinian to a depth of 10-12 meters. When we started working at the specified depth, there was not a single sign of an aquifer. We were sure that we were drilling through loam with stones and there was no way there could be water in them. There was no absorption at all, there was sand, but very fine and in very small quantities. The drilling was very slow and became even worse than before. We were dissatisfied and upset, anticipating failure, we cased the pipes to the depth suggested by Evgeniy and lo and behold. The well showed a flow rate of about 1 cubic meter per hour. So the above-mentioned signs help out drillers in the vast majority of cases, but it's not that simple and there are many nuances and exceptions that need to be paid attention to when drilling a well. This comes with experience. Many drillers who drill without logging are confident that they understand exactly everything that happens underground and see all the aquifers. But in fact, this is a banal survivor's mistake. A driller who missed an aquifer will never know that he missed it without logging. Sometimes we come across places where it is very difficult to understand exactly at what depth the aquifer is located. For example, there was such a situation. Drillers drilled a well 23.5 meters deep. They installed two filters - at a depth of 17.5-19.5 meters and 21.5-23.5 meters. You can see for yourself how much the guys missed. The well flow rate was about 300 liters per hour and the water was muddy, with sand. In theory, such a well should be redone, but the customers did not have money for a second well. Therefore, they suggested raising the pipe up a little by 1.2 meters. It is not known how it all ended, since we did not end up redoing this well. Example No. 2. Customers asked to do gamma logging and video logging of the well with complaints about dirty water. As you can see from the report, the first filter is much larger than the aquifer, and the second is generally below the aquifer. Due to this, water from the first aquifer gets into the well, washing away clay on its way. In this case, the water will not be clean. The verdict is to drill again. How do you determine the aquifer? Write in the comments. We are engaged in drilling wells in the Komi Republic, Syktyvkar and nearby areas. We make both Abyssinian wells and wells for 125, 120 pipes. Website - http://npaqua.ru/ Vkontakte group - https://vk.com/burenieskvaginsyktyvkar Odnoklassniki group - https://ok.ru/byrenie