Gas migration through cement columns has been an industry challenge for many years. Formation gas/influx can migrate through the cement column resulting in gas being present at the surface. To overcome gas migration on existing wells, remedial jobs are executed, which requires detailed engineering and testing prior field deployment. The objective of this paper is to detail the effort and experimental work that took place to use different polymer resin systems in Saudi Arabia gas wells. The two polymer resin systems are differentiated by their main component, either epoxy resin or polyester resin. The epoxy resin system is prepared by mixing an epoxy resin with an aromatic amine curing agent while the polyester resin system is prepared by mixing polyester resin with norpol peroxide curing agent, filler, and silicon dioxide. This study is the first to assess the performance of two different types of polymer resin systems and evaluate their remedial operations according to the authors’ best knowledge. In addition, this paper discusses operational challenges that may occur when using each type of polymer resin system. Lab tests were conducted to measure the thickening time, the rheological properties, compressive strength, and limitations for each polymer resin system. The tests suggest that a maximum temperature of 225°F and 275°F should be maintained when using the epoxy and polyester polymer resin systems, respectively. Based on the study, the epoxy resin system is easier to control as it is composed of only two components unlike the polyester resin system, which is comprised of several components. The lab study suggests operational recommendations to increase the probability of success of the polymer resin systems.

Drilling in a mature Saudi Arabian oilfield proved to be a steep but successful learning curve for a Saudi Aramco Engineering team. Over the years, the encountered challenges were handled by applying tested methods implemented in the area, which failed to turn around the desired results in this field. It became clear that field specific practices and procedures were necessary and, as a consequence, old paradigms were challenged to improve the performance while mitigating downhole challenges and eliminating excessive non-productive time (NPT). Problems typically confronted in the area were pinpointed using historical data revision, and analyzing of previous field experience regarding common drilling practices. Focus was placed upon troubles impacting the two intermediate hole sections in which a number of problems arose including time-dependent unstable shales and interbedded permeable layers with different pressure regimes. Improvement of drilling the sections of concern necessitated a drastic and systematic revision of many aspects such as drilling fluids, BHA design, and drilling drive. In addition, long lasting field specific drilling practices such as connection practices and wiper trips were challenged through technical analysis, aiming to boost operational efficiency. The recommendations were implemented in stages enabling evaluation of results, and ensuring a smooth transition from erstwhile practices. The new approach successfully assisted in overcoming drilling troubles, resulting in outstanding operational excellence levels. Wells were drilled faster and non-productive time (NPT) was significantly reduced. The results are benchmarked against wells delivered over a period of 4 years. As of today, the wells drilled and completed exhibited an outstanding improvement, increasing drilling rate of penetration and dropping NPT by 71%. Furthermore, the main key performance indicator (KPI), footage per day, has significantly increased by 44%. The paper presents the development of set of optimized practices and procedures that collectively replaced deep-rooted field practices that are not suitable for the modern-age ERD wells. It walks through the challenges, the thinking process, the technical evaluation, and field implementations. This optimization has resulted in a stellar increase in drilling performance while cutting back on non-productive time.

No abstract