Importance of Water Chemistry in Oil and Gas Operations—Properties and Composition

In the oil and gas industry, water is essential element since it exists in most of the stages, starting from drilling operations, then production processes including injecting in the reservoir to maintain the pressure, and finally disposing the produced water from the reservoir. Therefore, it is very important to understand the water in the petroleum industry with its different types and study its effects on the reservoirs as well as the downhole and surface equipment. Most of the studies and literature reviews focused on the oil and gas properties. In fact, understanding the properties of the water is as important as the oil and gas properties. Water is always present in the oil and gas fields during production, injection or disposal. Therefore, it has a direct impact on the productivity and overall efficiency of the field and the entire development project. This paper is going to illustrate and focus on several objectives. First, it elaborates the importance of the water in the oil and gas fields. Then, it includes a comprehensive overview of different types of water in the petroleum industry including a summary about of their properties. The main two types that the paper focuses on are the produced water and the injected water. It clarifies the effects of both of them on the reservoir, well completions and facilities. After that, the paper touches bases on the common problems and issues caused by water along with a brief summary of steps needed by the operators to follow in order to solve them. In addition to that, the common monitoring procedures and tests that are usually followed to observe the quality of the water are going to be presented. Finally, couples of solutions used by operators are reviewed to solve the problem of excessive water production after the water breakthrough in the field.