Zero-Flaring Technology Reduces Greenhouse-Gas Emissions

_ This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 222264, “Reducing Greenhouse-Gas Emissions by Using Zero-Flare Technology To Enhance Sustainability,” by Zeeshan Ahmad, SPE, Mohamad Mubarik Albadi, and Sunil Chitre, SPE, ADNOC, et al. The paper has not been peer reviewed. _ The complete paper describes a technology that combines a compression unit with a flexible line to offer a flaring alternative for transferring hydrocarbons to networks. The zero-flaring technology (ZFT) package consists of a gas compressor and triplex pump on one mobile skid, along with temporary reinforced thermoplastic (RTP) pipes to connect the well to the nearest production facilities. ZFT not only supports testing operations but also increases low-potential production with zero greenhouse-gas (GHG) emissions. Introduction Oil-rim reservoirs and high-water-cut wells often pose significant production challenges because of insufficient reservoir drive. These wells typically exhibit low flowing pressures at the wellhead, rendering them unable to flow within existing flowline networks. This paper discusses production testing conducted to activate such wells, in which observed flowing pressures ranged from 100 to 200 psi. The studied wells (a total of 26) are distributed across various limestone formation layers where gas depletion has occurred over the past 20–25 years, leaving oil predominantly at the reservoir edges or rims. The following challenges were faced in evaluating the oil-rim reservoirs in Field X: - The lack of adequate bottomhole flowing pressure and wellhead flowing pressure (WHFP) prevented produced gas and liquid from moving up the production tubing and entering the gathering manifold, separator, and production facilities. - The WHFP was too low to divert the wells to a separator, making it difficult to measure the well’s potential accurately. - The conventional testing and backflow methods resulted in the emission of hydrogen sulfide (H2S) and CO2 into the atmosphere as a result of flaring. - Flaring produced hydrocarbons, especially when production facilities are unavailable or WHFP is too low, leads to substantial revenue loss. These wells were drilled between 2003 and 2010; flowline-facility integrity was suboptimal because of long periods of inactivity and safety and environmental concerns after assessment results. The operator’s team sought advanced technology in the market to perform well-testing operations with zero emissions of GHG and CO2. ZFT Package ZFT is an effective solution to protect the environment from unnecessary flaring. The authors write that, for the first time, this package was used with a low-pressure/high-pressure gas compressor and triplex pump in one mobile skid and temporary RTP to connect the concerned well to the closest production line instead of flaring the well fluids during the testing period (Fig. 1). This application can be used to perform flowback operations and zero-flaring well-testing and revival operations. Also, the ZFT package can handle sour gas (up to 20% H2S and 40% CO2) using certain measures and special precautions. Use of the RTP system in an oil-dominant flow regime is well-established in the industry; however, wet gas applications with a higher partial pressure of H2S are still the subject of study.