Chapter 4: Chemistry of Product Flow Impairment in Pipelines and Facilities

The transportation of oil/gas from the field can be severely impaired if scale or organic deposits exist anywhere in the piping leading from the reservoir to the sales point. In the oil/gas industry, control of deposits in various pipelines, as well as in the near-wellbore region, is termed “flow assurance” (FA). General reviews of FA issues and programs are in Borden (2014), in Brown (2002), and in Frenier et al. (2010).

Deposits in the piping leading to injection wells can also affect production. Any deposition in piping reduces the diameter available for flow and can therefore choke the transport into the reservoir required to maintain pressure or for enhanced-oil-recovery (EOR) processes. The additional pressure drop because of deposit buildup can be quite large. The pressure drop relationship to the flow rate for single-phase pipe flow is given as Eq. 1.8. Also review Section 1.4.2. The various types of deposits described in this chapter can also affect the corrosion processes discussed in Chapter 3. These include pitting, underdeposit corrosion (UDC), and erosion/corrosion as well as general corrosion. Campbell (2002a) describes a direct link between the solids in a line and general coupon-determined corrosion rates. As shown in Fig. 4.1, data from this author indicate that the general corrosion rate decreased markedly after comprehensive cleaning and reached the company’s target corrosion rate after implementation of a new inhibition program.