Solids problem at the ring border gas plant

Natural gas production from the Ring Border Montney formation presents unique problems related to solids deposition during processing since the produced fluids (gas and condensate) contain suspended and dissolved solids. Solids deposition occurs not only in the plant inlet separators but also in the various gasstream and condensate-stream operating units. To address the solids problem at the plant, a large number of deposited solids and condensate samples from several operating units were collected and characterized. Results of the characterization studies indicated that all types of samples contain various amounts of asphaltenes, wax, insoluble organic carbon, and formation fines. Precipitated asphaltenes were identified as the major contributor to the solids problem. Commingling of two compositionally incompatible condensate streams (one from the low temperature separator and the other from the inlet separators) was found to significantly augment solids deposition in the plant by precipitating out asphaltenes which were initially dissolved in the condensate. Asphaltene precipitation experiments carried out in the laboratory confirmed the compositional incompatibility of the two condensate streams. Various possible remedial strategies such as chemical injection and process modifications have been evaluated by means of laboratory testing and process simulation. It was found that chemical injection is not effective for preventing asphaltene precipitation at economical chemical injection rates. The process modifications which are recommended to solve the solids problem in the condensate processing units involve separate stabilization of the two incompatible condensate streams and removal of the precipitated asphaltenes downstream of the process using a sedimentation tank.