Factors Influencing the Quality of Petroleum Cementing and Strategies for Improvement
Abstract: With advancements in technology, cementing has become widely utilized in petroleum extraction. Various factors can affect the quality of petroleum cementing during the extraction process. Therefore, petroleum extraction companies should develop effective strategies to address common issues encountered in cementing to improve the overall quality of the operation. This paper first analyzes the main factors influencing the quality of petroleum cementing and then explores measures to enhance its quality, aiming to provide valuable references for related research.
Keywords: Petroleum cementing quality; influencing factors; coping strategies
Introduction: In the context of continuous development in China’s petroleum industry, cementing technology has become a primary method in petroleum extraction. Due to the harsh environments where most petroleum extraction takes place, the quality of cementing is easily influenced by external factors. Thus, petroleum extraction companies should comprehensively consider these influencing factors and formulate preemptive strategies to enhance extraction efficiency.
1. Main Factors Influencing the Quality of Petroleum Cementing
1.1 Drilling Fluids The parameters of drilling fluids directly impact the quality of petroleum cementing. If the density of drilling fluids is low, creating a significant difference with the density of cement slurry, it increases the buoyancy of drilling fluids, promoting the smooth progress of petroleum drilling operations. Conversely, if the density of drilling fluids is high, the buoyancy decreases, adversely affecting the normal operation of petroleum cementing. The viscosity of drilling fluids is usually affected by fluid loss. When the fluid loss is significant, the viscosity decreases, while low-viscosity drilling fluids increase the flow rate, aiding petroleum cementing operations. On the other hand, low fluid loss results in higher viscosity, reducing the flow rate, which negatively impacts petroleum cementing.
1.2 Stratigraphic Rock Properties Analysis of geological conditions reveals that different stratigraphic rock layers directly influence the quality of petroleum cementing. As the second interface in petroleum cementing, mainly composed of cement sheaths and underlying strata, the focus of extraction teams should be on special stratigraphic rock properties during extraction operations because oil wells can be directly impacted by formation pressure leading to water influx issues. This can result in reduced compactness at the cement bonding position, affecting the performance of cementing. Additionally, the rock properties of the formation and the formation sound velocity have a direct relationship, influencing the level of cement bonding. When cement slurry is used, due to the formation’s absorbency, fluid loss occurs, causing numerous cracks. Once cracks appear, the likelihood of wellbore collapse increases. To achieve good quality in petroleum cementing and maintain the stability of the wellbore, personnel need to conduct field inspections, formulating suitable plans considering specific geological conditions. By closely monitoring changes in reservoir pressure, the probability of formation cracking can be reduced.
1.3 Cement Slurry Due to the tendency of cement slurry to settle and separate, it can directly impact the quality of cementing. When cement slurry settles and separates, if it solidifies promptly, it does not negatively affect the quality of petroleum cementing operations. However, if solidification is delayed, numerous cracks may form, directly impacting the overall quality of the project. Factors influencing the setting time of cement slurry primarily include external and internal factors. External factors include the circulation speed in the annular space and the length of the cemented section. Controlling the cemented section length between 800-1200 meters and increasing the annular circulation speed can enhance the quality of cementing operations. Internal factors include the flowability and density of cement slurry. As the density increases, so does the quality of cementing operations. Therefore, petroleum extraction companies should appropriately increase the density of cement slurry to enhance the efficiency of cementing. When managing the flowability of cement slurry, personnel should choose feasible optimization adjustment plans based on specific circumstances.
2. Measures to Improve the Quality of Petroleum Cementing
2.1 Enhancing Drilling Fluid Performance In petroleum cementing operations, personnel should optimize the density and fluid loss of drilling fluids based on their properties, reconfiguring the drilling fluids as necessary. Analysis shows that when the fluid loss of drilling fluids is between 5-7 milliliters, the quality of petroleum cementing can reach an optimal rate of 80%. Furthermore, to minimize the impact of mud cakes on petroleum cementing, extraction companies can use low-permeability drilling fluids, enhancing the performance of drilling fluids and improving the quality of petroleum extraction.
2.2 Improving the Performance of Cement Slurry Controlling the density of cement slurry within the range of 1.95-2g/cm³ and ensuring fluid loss is less than 110 milliliters can benefit petroleum drilling operations. Adjusting the thickening time of cement slurry according to actual conditions can avoid the impact of high air humidity on the cement sheath. Additionally, controlling the fluid loss of cement slurry can reduce the impact of excessively high or low fluid loss on the quality and performance of cement slurry. Personnel can add appropriate amounts of diphosphates to the cement slurry to reduce gel strength and improve displacement efficiency. Using corrosion-resistant and impermeable cement slurry systems in petroleum cementing operations can reduce fluid loss while enhancing impermeability and corrosion resistance, minimizing the impact of stratigraphic rock properties on cement slurry setting time and improving the bonding strength between interfaces, thereby enhancing the performance of cement slurry.
2.3 Strengthening Quality Management and On-Site Supervision
2.3.1 Emphasizing the Quality of Petroleum Cementing Operations As the final procedure in petroleum drilling operations, cementing plays a vital role in protecting oil and gas resources. Personnel should refine the design of cementing projects to extend the useful life of oil fields and enhance environmental protection efforts. Therefore, managers of oilfield extraction should prioritize the quality of cementing operations, providing security for subsequent cementing technologies.
2.3.2 Enhancing Supervision and Management of Petroleum Cementing Operations To improve the effectiveness of petroleum cementing projects, implementing effective construction management methods can help identify and eliminate potential hazards early on. Therefore, oilfields should establish petroleum management regulations and create comprehensive quality and safety management mechanisms for cementing operations. Based on specific production requirements, professional personnel should be assigned to conduct rigorous on-site supervision of cementing operations, ensuring the implementation of technical measures and achieving the desired outcomes. Additionally, managers of petroleum cementing operations should enhance the management of construction materials to prevent substandard products from entering the construction site, affecting the quality of petroleum cementing operations.
2.4 Improving the Quality of Workers’ Operations With experience accumulated over time, the petroleum extraction industry has continuously increased efficiency. High demands are placed on the cementing skills of petroleum extraction workers. Extraction companies should prioritize the importance of petroleum cementing operations and provide adequate technical support. Given the unique geographical environments of oilfields and the challenging nature of petroleum cementing, there is a shortage of skilled workers in this field. Moreover, the varying levels of professional competence among workers directly affect the outcome of cementing. Therefore, companies should organize specialized training sessions regularly to improve the professional skills and operational capabilities of workers, enhancing the standardization of cementing operations and the overall quality of petroleum cementing work. Additionally, during external recruitment, companies should raise the entry threshold, hiring workers with high professional skill levels and certification.
Due to the high intensity of petroleum extraction work and harsh cementing conditions, the petroleum extraction industry faces a high turnover rate. Companies can mitigate this issue by offering competitive salaries and benefits, and implementing incentive systems to boost worker motivation. Furthermore, establishing a comprehensive reward and punishment system can recognize and reward workers who perform exceptionally well in petroleum cementing operations, ensuring the smooth progress of cementing work.
Conclusion: In summary, during the execution of petroleum cementing operations, external objective factors and human factors can adversely affect the quality. Petroleum extraction management companies should emphasize the importance of cementing operations, focusing on enhancing the performance of drilling fluids and cement slurries, and strengthening quality and supervision management of petroleum cementing operations. These efforts can achieve the goal of improving petroleum drilling efficiency.