INTERNATIONAL JOURNAL OF SCIENTIFIC & TECHNOLOGY RESEARCH VOLUME 9, ISSUE 03, MARCH 2020 ISSN 2277-8616 1395 IJSTR©2020 www.ijstr.org Improving Zonal Isolation With Foam Cementing Rizki Akbar, Rini Setiati, Abdul Hamid Abstract— Cementing is the most important part of well construction and requires effective compatibility with nitrogen (N2) additives. Some of the challenges associated with this process are high temperatures, brine corrosion, and CO2 gas. The cementing process in geothermal wells is similar to oil and gas with high displacement efficiency to ensure adequate processing during low velocity. This study, therefore, aims to determine the function of foam cement using nitrogen to improve zonal isolation. The low use of variable density and relatively high strength of the foamed cement help operators to achieve long-term hydraulic bonds and zonal isolation by preventing hydrostatic pressure damage. In Indonesia, geothermal wells are developed with the fracture and low temperature gradients using lightweight foamed cement. This ensures job success, proper engineering, and control.. The results foam cementing are to establish good bonds and zonal isolation, the engineering process allows operators to adjust slurry density during cementing as needed. It is first mixed then pumped into a hole, and stabilized to create foam. This study concludes foam pumping has the ability to improve zonal isolation in oil and gas drilling wells. Index Terms— cement, slurry, nitrogen, zonal isolation, foam, engineering. ——————————  —————————— INTRODUCTION Cementing process is the way of placing cement into annulus between casing and wellbore. For achieve this purpose, hydraulic sealing have to obtain casing and cement, also casing and cement, in the mean time preventing the chanelling. For this main requirement for cementing oil and gas wells are [1] to tying and supporting the casing, limiting the movement of fluid between formation and sealing the lost circulation zone. Nevertheless, there are several factors causing failure cementing process, such as cause of mechanical shock of pipes and extension of the casing. Pressure causes conventional cement to break down quickly, thereby, creating a new flow in the annulus. Furthermore, continuous casing pressure (SCP) is generated when the pressure returns to the annulus after thermal expanded of the fluid and closure of the valve. The compressible and flexible nature of cement tends to flex and absorb pressure, which damages conventional cement. Its flexibility without foaming tends to increase cementing lifespan by maintaining the integrity of the hydraulic bond, preventing the formation of microannules, and eliminating pressure cracks. 2. METHOD OF THE RESEARCH Foam cement is a mixture of slurry, foaming agents, and nitrogen gases. When mixed with the correct composition, it forms a stable and lightweight slurry. In development of foam cementing must suitable with base-water. Stable base-water slurry cement have a same mechanism that will produce free fluid depend on properties of set foamed cement. [1]. The cement slurry is first mixed and pumped into the well, which is followed by the injection of a proportional amount of high pressure N2. The layout of producing a sample foam is presented in Figure 1. Nitrogen is put into the cement slurry with adequate energy to produce descriditated gas cells, thereby producing a stabilized and unconnected product in the form of bubbles. These bubbles are not fused (Figure 2), thereby producing a cement matrix with low-density permeability and high strength. For example, slurries are bubbled up to densities as low as 4 lb /gal and are easily placed in weak formations, thereby preventing problems associated with lost circulation and fallback. Foam cement tends to support the functions of primary cementing and repairing for offshore and onshore usage, as shown in the following list [1]: 1. With some additives of cement, foaming creates a synergistic effect that enhances its properties. This effect is proven by some additives which lose fluid, material circulation, and latex. 2. The density of foam cement varies. Its ductility allows expansion and maintenance of pressure during hydration, thereby assisting in the production of long- term zone isolation. When cement expands, it fills the swept hole, and the circulation zone disappears very broadly without damaging the formation. 3. Increased sludge removal capacity from foam cement also helps to improve zonal isolation. Furthermore, its tenacity provides sheath support for wells. ————————————————  Rizki Akbar, Petroleum Engineering, Faculty of Earth Technology and Energy, Trisakti University, Jakarta, Indonesia, PH+6281315557735. E- mail: rizkiakbar@trisakti.ac.id  Rini Setiati, Petroleum Engineering, Faculty of Earth Technology and Energy, Trisakti University, Jakarta, Indonesia, PH+628158848400. E-mail: rinisetiati@trisakti.ac.id  Abdul Hamid, Petroleum Engineering, Faculty of Earth Technology and Energy, Trisakti University, Jakarta, Indonesia, PH +6285714830320, E-mail: abdulhamid@trisakti.ac.id