Kianoush Pooria, Mesgari Farough, Jamshidi Emad, Gomar Mostafa, Kadkhodaie Ali, Varkouhi Shahab
Department of Petroleum and Mining Engineering, South Tehran Branch, Islamic Azad University, Corner of Kausar Blvd., Deh Haghi (Ahang) St., Southern Nabard Blvd., Pirouzi St., Tehran, 1777613651, Iran.
National Iranian Oil Company, Exploration Directorate (NIOC-EXP), Khodami St, Seoul St, NE Sheikh Bahaei Sq, Tehran, 1994814695, Iran.
Sci Rep. 2024 Nov 29;14(1):29653. doi: 10.1038/s41598-024-81269-2.
The oil and gas industry's reliance on well cementing practices to ensure well integrity and productivity is a pressing concern, particularly in exploratory wells where unpredictable conditions can lead to subpar cement bonding efficiency. This study addresses the pressing issue of optimizing cementing practices in Iran's exploratory wells, ensuring better well integrity and productivity. The preliminary objective is to investigate the impact of hole size and bottom hole temperature variations on cement bonding efficiency in these wells. We analyzed cement quality logs from 21 exploratory wells in reservoir zones between 2012 and 2022 to achieve this. The study employed a systematic approach, using CBL/VDL and cement formulation to assess the quality of each wellbore section separately. We designed a cement formulation based on changes in bottom hole temperature and gas migration control and implemented it using three different contractors, each with unique additives. It allowed us to compare the quality of cement resulting from different phases and additives. Our results show that cement designed with dominant liquid additions in the 5-inch liner phase exhibits better bonding than formulations with increased powder form additives, specifically those containing a liquid dispersant, liquid fluid loss controller, liquid anti-gas migration, and liquid H.T. retarder for LNR 5 inch. Additionally, smaller hole sizes demonstrate better cement bonding quality due to reduced fluid flow and less turbulence. These findings have significant implications for optimizing cementing practices in the petroleum industry, particularly in Iran's exploratory wells. Overall, this investigation provides valuable insights for improving wellbore integrity and productivity by optimizing cementing practices, which can be applied to future drilling operations in Iran's exploratory wells.
石油和天然气行业对固井作业的依赖，以确保井的完整性和产能，这是一个紧迫的问题，特别是在探井中，不可预测的条件可能导致水泥胶结效率低下。本研究解决了伊朗探井中优化固井作业的紧迫问题，以确保更好的井完整性和产能。初步目标是研究井径和井底温度变化对这些井中水泥胶结效率的影响。为实现这一目标，我们分析了2012年至2022年期间21口探井储层区域的水泥质量测井数据。该研究采用了系统的方法，使用声波变密度测井（CBL/VDL）和水泥配方分别评估每个井筒段的质量。我们根据井底温度变化和气体迁移控制设计了一种水泥配方，并由三个不同的承包商实施，每个承包商都有独特的添加剂。这使我们能够比较不同阶段和添加剂产生的水泥质量。我们的结果表明，在5英寸尾管阶段以主要液体添加剂设计的水泥比增加粉末状添加剂（特别是含有液体分散剂、液体降滤失剂、液体防气窜剂和液体高温缓凝剂的LNR 5英寸水泥）的配方表现出更好的胶结效果。此外，较小的井径由于流体流动减少和湍流较小，显示出更好的水泥胶结质量。这些发现对优化石油行业的固井作业具有重要意义，特别是在伊朗的探井中。总体而言，这项调查通过优化固井作业为改善井筒完整性和产能提供了有价值的见解，可应用于伊朗探井未来的钻井作业。
