TABLE OF CONTENTS Raw natural gas after transmission through the field-gathering network must be processed before it can be moved into long-distance pipeline systems for use by consumers. The objective of gas processing is to separate natural gas, condensate, noncondensable, acid gases, and water from a gas-producing well and condition these fluids for sale or disposal. The typical process operation modules are shown in Figure 4-1. Each module consists of a single piece or a group of equipment performing a specific function. All the modules shown will not necessarily be present in every gas plant. In some cases, little processing is needed; however, most natural gas requires processing equipment at the gas processing plant to remove impurities, water, and excess hydrocarbon liquid and to control delivery pressure. The unit operations used in a given application may not be arranged in the sequence shown in Figure 4-1, although this sequence is typical. The choice of modules to be used and the arrangement of these modules are determined during the design stage of each gas-field development project (Meyer and Sharma, 1980).
Unfortunately, at the individual module level the design may be sound and the operation correct but could result in a poor gas processing facility. The reason is that each module has varying characteristics under varying loads, which can result in a type of internal incompatibility. For instance, a given unit module may require a particular inlet composition to produce the desired output. If a previous unit does not maintain this, the downstream...
