Controlled-release chemicals in oilfield application: A review

Various specialty chemicals are used from exploration and production to transmission in oil and gas industries . However, many of these oilfield chemical treatments are injected into wells that are released in full at one point upon the addition, and effectiveness lasts for a short time. Controlled-release technology can make the effectiveness of active chemicals last for an extended period in the application. Hence, it also reduces the negative impact of excess chemicals on the environment. Controlled-release technology has begun to play an important role in the oil and gas industries. This paper reviews recent advances and the application of the controlled-release techniques in enhanced oil and gas recovery, flow assurance, asset integrity management, stimulation, and chemical tracer in the oil and gas industry. Novel nanocomposite and encapsulate materials were described. The preparation for the control of released active substances and their released mechanism are also discussed. Applicability in high temperature, pressure, and salinity reservoirs was emphasized. The challenges for the field application of the controlled-release technique in the oil and gas industry are also addressed. • Controlled release inhibitors increase scale, paraffin, asphaltene, and corrosion inhibitive time. • Encapsulated surfactants reduce their adsorption during EOR. • Core-shell encapsulates control release gel breaker and gelation time. • Controlled released extended effective period of foam and tracer.