Most people think that oil and gas are found sitting in a space somewhere under the ground in a vast underground lake of oil. The hydrocarbons though actually exist in layers of porous rock that has been overlaid by rock that is knows as shale – impermeable rock. The rocks that contain the oil however are two sedimentary rocks namely limestone and sandstone. Some of the rocks have interconnected pores that allow the oil to pass through them. In addition to the oil, water and gas also exist in the said reservoir.
Basically underlying the oil is the water and it is referred to as formation water or connate. Connate water was trapped within the rock when the rock was forming. With time, the composition of connate water can change. Formation water on the other hand is water that was formed in situ. Once formed it is trapped along with the hydrocarbons inside the impermeable rock or shale. When the work of mining for oil and gas commences, the oil, gas and water are extracted from below ground. The process of extraction is known as fracking or hydraulic fracturing. Fresh water is injected into the ground breaking up the rocks that carry the oil, gas and water. The water coming from this process is knows as produced water.
Produced water disposal in Texas has been a topic of discussion due to the many challenges faced by the oil and gas companies. Once the water comes to the surface there oil must be separated from it. The water is not clean at all and in fact often contains toxins. The oil to be removed may come in the form of droplets or even in solids. Then there are hydrocarbors as well as gasses including carbon dioxide which is quite corrosive, as well as other lighter ones. In addition any water soluble chemicals that may have been used will be found in this water. This calls for safe treatment methods before the water can either be reused or disposed off.
There are several methods of produced water disposal in Texas. If the water is not treated it is trucked a long distance away to disposal wells where it is injected far beneath the ground. The other option is to that the water trucked to water treatment facility where it goes though the process and is then discharged into the sea, rivers or estuaries in the surrounding areas.
Produced water disposal in Texas has been well thought out so as to protect the environment. It can go into disposal wells under the earth or treated and discharged.