In the eyes of laymen, oil extraction is similar to water wells. In fact, oil extraction needs to go through a series of processes such as exploration, determining the position, number and depth of wells. In the drilling process, technical equipment (including drilling rigs, derricks) and a set of lifting system and drill rods, drilling tools and drill bits are also required. Drilling fluid is related to the environment, reservoir and petroleum quality. Oil extraction is not easy. How to use potassium formate to "extract" oil from deep wells?

The oil was originally buried deep in the formation, and there was huge pressure from the overlying rock formation and formation water. Before drilling to open the reservoir, the pressure is in equilibrium. Once the formation above the oil layer is opened, this balance is broken, and oil flows from around the well to the bottom of the well where the pressure drops suddenly.

The potassium formate is mainly responsible for potassium ions during operation, and can completely dissociate. When the same amount is added, the effective K concentration is higher than that of potassium chloride, and there is no pollution of anion chloride. The surface tension of the filtrate is significantly greater than that of the potassium chloride drilling and completion fluid system, and the flow resistance into the formation is large, which not only inhibits the hydration and dispersion expansion of the clay, prevents the formation from shrinking, but also does not interfere with the electrical measurement, and is lightly corroded.

In addition, petroleum often contains a lot of natural gas. It is almost inseparable from the oil in the formation, like a bottle filled with soda. Drilling is like opening the lid of a soda bottle. With the expansion of dissolved gas, the oil in the oil layer first rushes to the wellbore and then is ejected from the wellhead by the wellbore, so the protection of the oil and gas layer is crucial.

The filtrate activity of potassium formate is low. In ultra-low permeability reservoirs and shale formations, the principle of activity balance is used to achieve its inhibition, reduce the content of useless solid phase in the drilling fluid, and appropriately reduce the density of the drilling fluid to achieve The purpose of protecting the reservoir. At the same time, the pollution of the oil layer is avoided.

Normally, petroleum is not stored directly in the ground in the form of a large amount of liquid. The relatively high-quality kerogen produces oil under pressure under the influence of gravity. Most oil fields do not have such good conditions, and the exploitation of such oil fields is generally expensive. Potassium formate system has strong suppression and anti-collapse ability, excellent rheological sand-carrying performance and water loss, reasonable cost, regular bore diameter, and low accident rate, which can greatly reduce mining costs.