Recently, the Bohai Sea discovered 100 million tons of large oil fields. The discovery of large oil fields is a good thing for the country, it is even better for Sea oil, and it is also helpful for achieving national oil self-sufficiency. Underground resources such as petroleum, rare earth, and minerals are products of nature. For offshore oil exploitation, it is necessary to use drilling fluids such as potassium formate that can protect the oil layer to reduce the difficulty of mining and rationally exploit resources.

The exploitation of offshore oil is a highly complex and unstable process, and it is said that drilling fluid is the "blood" of the drilling industry. If there is no drilling fluid with good performance and sufficient quantity, or if the drilling fluid cannot be circulated normally due to some reason (such as formation loss and drilling tool breakage) during drilling, the drilling work will not proceed. Sometimes it will seriously endanger the "life" of the well.

At present, the Bohai Oilfield has formed reservoir protection technologies for different geology and reservoir characteristics. Potassium formate drilling fluid can be well used and can meet the following characteristics:

1. The improved small cation can reduce the density of drilling fluid, improve the pressure sealing capacity of the formation, prevent leakage, and prevent water lock damage to medium and low reservoirs.

2. Wellbore reinforcement and collapse prevention. Potassium formate drilling fluid can promote the smooth flow back of low-permeability reservoirs, with strong plugging, strong suppression and strong collapse prevention.

3. High temperature solid-free drilling fluid system. Potassium formate drilling fluid has the characteristics of no solid phase and good protection effect on the reservoir. The high temperature resistance is greater than 150 ° C, which can ensure the high temperature operation of the drilling equipment and automatic glue breaking. The solid-free weak gel quickly blocks the perforated well section and reduces the completion fluid loss.

4. Blocking PRD drilling fluid system. By adjusting the addition ratio of potassium formate drilling fluid, the filtrate and Shahe Street formation "activity" match. And through the principle of charge neutralization, potassium formate drilling fluid has high ion concentration and strong ability to compress the double layer of clay colloidal particles. Greatly improve the inhibition of drilling fluid itself, inhibit the hydration and expansion of deep shale shale, to prevent mud shale collapse. This solves the technical problem of safe drilling of weak gel drilling fluid mudstone interlayer under low solid phase conditions.

The drilling industry knows that the cost of offshore drilling is high, but it is the key to reservoir protection. It is also a strategy to reduce the development cost by using potassium formate drilling fluid to drill and complete wells quickly and safely. Potassium formate drilling fluid assisted the large and medium-sized oilfields in the Neogene, and made the oil and gas exploration in the Bohai Sea more brilliant.