When it comes to Borehole inspection requirements we can think of various industries and environments that these activities are engaged in. Underground deep drilling inspection camera for Geological Survey are becoming more frequent.
Of course, when it comes to well inspections, we may immediately think of water well borehole inspections that are performed primarily in residential areas. The purpose of well inspections is to identify issues before a greater problem manifest itself. The borehole camera or downhole camera is designed to view critical areas of the well to provide visual confirmation to make good maintenance or repair decisions. The borehole cameras save time and also protect the inspectors from having to enter a confined space. The borehole cameras are not only convenient but also highly productive. The well cameras are designed to provide a enough built in lighting to clearly see the inspection area as ambient light cannot be introduced. Most of these systems will offer a flexible cable as the vertical inspection is downward and does not require the standard rigidity that is offered in push cameras. As the wells can be in excess of 500 feet these systems usually offer a drum to introduce the cable to the inspection area as well as to retrieve or roll up the cable to remove the camera from the inspection area. Most drums are motorized to assist with this task but there are some lower cost systems will offer a manual drum.
Most all well inspection cameras and downhole cameras are waterproof. If you are introducing the camera head into a well that has deep water in it you need to confirm the BAR rating of your camera head. The deeper depth of water the greater BAR rating you will require. If your inspection camera does not offer the adequate design to be introduced to the high pressure, the camera will fail.
Geological camera inspections and Mining camera inspections can be completely different in that you may desire to perform a horizontal inspection or even to push the camera in an upward direction.
In speaking to one of our customers Jimmy L, Geological Engineer, he states, “In my experience in the limestone industry (especially in the Midwest), this type of geologic camera work is becoming more and more common (though it’s still specialized and relatively low volume). Typically, we buy purpose-built cameras from mom-and-pop shops, but there is a growing market for mining end users.
We have 14 or 15 underground mines (though not all need these cameras) the units typically last quite a few years once we invest in new ones. I’ll let you know our specific needs so you guys can keep an eye out for products.
The cameras are utilized in relatively hostile environments (as opposed to just the camera head and probe, like in an engine or pipe). Water (commonly acidic), dust, mud etc. are common. We typically scope holes that are 5’ to 25’ deep and are 2” (most common) to 5” diameter. Focal length does not need to be adjusted on the fly, or at all, as long as it is set to the ID of the bore. Dust for example embeds all of the foam in a pelican case, and can work into all of the electronic connections (this is more of an inconvenience and maintenance issue, but worth noting.) Its not uncommon for the drilled holes to produce water, sometimes as much as a garden hose, sometimes a trickle (I have dropped cameras into waist deep water – uncommon, but worth noting). This makes viewing hard to impossible, but it also can bring water down the cables into the camera case, or users’ arm. Typically, cameras are used from mobile equipment like manlifts (notoriously bouncy). As such, when the cameras are larger, they are typically strapped to the equipment as there is a mobile aspect to the work and the cameras are used in an elevated work space (5’ to 60’ off the ground). The camera needs to be rotated to view all internal surfaces of the bore. Large, spool type sewer camera’s make this hard, as they can only be rotated as a whole unit, or by twisting the wire, which is difficult. The best camera’s we have used have been flexible cables which we fish with quick connect poles into and out of the hole. The users are remote in environments that have zero light typically (besides headlamps) and connectivity to other devices (besides Bluetooth). Long battery life is best. Fire is a significant and serious hazard in underground mines. We don’t need intrinsically safe equipment, but the batteries were a concern when Li-ions, and Li-po’s were first developing. During these early high energy batteries, we used lead acid instead to mitigate fire potential. The new generations of batteries are much better, so this is less of an issue. The camera is inserted into a hole that commonly has mud and dirt caked onto the inside, so it easily gets obscured if it is forward facing. This occurs mostly when the camera head is flat, forward facing and recessed. It’s a little cup that grabs debris. A coned or domed housing works well, but affects the optics. Sapphire lenses covers and or housing is best as glass gets abraded very quickly. For these reasons along with the need to have very detailed viewing, side facing cameras are best. The ability to switch between forward/ side view is a game changer though. The cable and wires can get pinched in articulating pieces of equipment, and easily stepped on. Generally, most camera users are conscious of the fragility of the equipment, but mines are famously hard on equipment.
We don’t necessarily need a precision instrument as much as a user-friendly durable one. We are interested in finding cracks, separations, and seeing the type of rock. Nice color/ LEDs, resolution, recordability, simplicity and durability are important.
Underground infrastructure inspection professionals have to meet specific needs in day-to-day operations. The development of Inspection cameras systems products significantly improves the efficiency, time savings, safety and profitability of inspection operations. These inspections may be performed horizontally or vertically. The data can be captured with pictures or streaming video on the removable SD card or USB drive. Although these systems will be used in mining, large borehole or other geological inspections you very well may find these same devices marketed as a pipe inspection camera.
For many of these inspections an inspection camera with pan and tilt features is very useful. This will allow the inspector to view a full 360 degrees of the inspection area. In addition, many of the push cameras offer HD image quality and some of the more advanced inspection cameras will offer remote focusing. The focusing capabilities will allow the borescope inspector to dial in and focus in on a specific area. This fine tuning of the inspection area can prove to be invaluable to critical inspection areas. HD image quality push cameras are becoming more popular as technology increases and pricing decreases across the market.
The old standard method of sending operators in for direct visual inspection can quickly become a huge expenditure and also inefficiently allocates resources that are often scarce and required for other important tasks. In addition, the subjective inspection and word of mouth report could be inadequate to make good business decisions. Having hard data such as pictures and videos of the inspection are proving invaluable in making business decisions.
Specifically, in the coal industry there are many federally mandated safety requirements and the on-site staff are required to abide by the safety regulations. Any and all confined space activities are regulated by OSHA and permits as well as strict regulations must be adhered to. In any situation where a camera can be entered into instead of a human is preferred. The risk associated with introducing a camera into a confined space or risky area is well worth it compared to the value of a human life.
When considering borehole camera inspections or downhole camera inspections you may think of Civil Engineering inspections. Many of these inspections surround manhole inspections and although these entry points are much larger than boreholes, some of the same inspection equipment is used to perform these types of inspections. Sometimes crawlers are used to inspect between manholes to confirm the integrity of the supporting pipes. For just inspections for the manhole itself some prefer to use a pole camera or a telescoping camera to perform this inspection. The telescoping pole camera is ideal for manhole inspections that need to be addressed quickly without having to physically break the plane of the confined space.
Instead of using a crawler many inside the manholes, many sewer camera professionals will use a manhole camera that provides enhanced zoom capabilities with high intensity LED lights to inspect between the manholes. Benefits of borehole visual inspections for Engineers and Scientist are increasing as the industry progresses into more safe and environmental initiatives. By being able to visualize rock structure under the surface of the ground the samplings and data provided the subsurface exploration professionals allows for further investigations, evaluations and decision making.
Push cameras are the perfect device for these types of inspections are the push rod on the camera is semi rigid and allows you to push the camera head over a long distance. The clear imaging and built in LED lighting make the accuracy and applicability of the push camera system ideal for borehole inspections.
In some inspection areas such as coal or other hazardous environments you may have to consider an intrinsically safe inspection camera such as the P374 camera. You can read more about this product on the hazardous inspection camera blog.
The P374 is a certified intrinsically safe inspection camera that offers a 1 inch diameter camera head with 200 feet of working length.