Increasing reserves in a mature giant; Wilmington Field, Los Angeles Basin; Part II, Improving heavy oil production through advanced reservoir characterization and innovative thermal technologies

Enhanced recovery of low-gravity oil from unconsolidated, high-porosity, high-permeability sands in the supergiant Wilmington field began in the early 1960s. Despite nearly four decades of production, postprimary recoveries have been generally low due to reservoir heterogeneity and operational problems. In particular, streamflooding has yielded poor results because of elevated steam:oil ratios, early steam breakthrough, and consequent premature equipment failure. A multidiscipline effort to address these problems and improve recovery is underway as part of the U.S. Department of Energy Class III (slope and basin clastic reservoir) Oil Recovery Field Demonstration initiative. In the fault block IIA portion of Wilmington field, this effort has focused on several main objectives. Those objectives discussed in this paper include (1) three-dimensional geologic modeling to rigorously define important relationships; (2) rock typing and rock-log modeling to improve reservoir characterization; (3) testing the feasibility of using horizontal wells in steamflood operations at Wilmington; and (4) employing a novel, low-cost completion technique applicable to unconsolidated formations. To date, significant levels of success have been achieved with regard to all these objectives. When complete, the project at Wilmington field should have wide-ranging application to similar reservoirs throughout southern California and elsewhere.