Overcoming Formation Damage and Increasing Production Using Stackable Frac Packs and High-Conductivity Proppants: A Case Study in the Wilmington Field, Long Beach, California

Abstract

Most successful completions in the Wilmington Field, Long Beach, CA, must address two concerns:formation sand control anddamage bypass / reservoir stimulation. For many years the completion strategies in this field have included some combination of conventional circulating gravel packs and fracture stimulations using resin coated sand. Recent evaluations have demonstrated that inadequate proppant conductivity is restricting well production. This led to fracture stimulation of wells with high quality ceramic proppants. Even in a modest stress environment, ceramic proppants increase conductivity and reduce non Darcy effects, thereby resulting in more productive fracture treatments. To bypass formation damage and increase production via fracture stimulation, while maintaining sand control in an economic fashion, an annular, stackable frac pack technique was employed. The sand control treatments were designed to be durable, low skin, and provide excellent wellbore to formation connection. The disadvantages of frac packs and ceramic proppants are complexity and cost. In older fields where margins are tight, these disadvantages may seem to outweigh the advantages and can erroneously remove frac packs and ceramic proppants from consideration. However, the authors found that combining simple, economical, stackable frac pack tools with ceramic proppant resulted in completions with higher production and more robust economics than prior completion practices. Introduction In 2004, nine wells in the Long Beach Unit were completed with multiple-stage, annular, stackable frac packs utilizing manmade ceramic proppant. These wells were completed in two horizons, the Union Pacific (UP) and the Lower Ranger. This is the first successful application of stackable frac packs in the Wilmington Field offshore Long Beach, California. The initial production rate (IP) of the nine wells averaged 57% above the expected rate based on offset producers resulting in a 40% gain in Net Present Value (NPV) and a 12% reduction in development cost per barrel oil vs. prior completion practices Wilmington Field Overview THUMS Long Beach Company is a wholly owned subsidiary of Oxy Long Beach Inc. THUMS is the contract operator of the Long Beach Unit (LBU) of the East Wilmington Field for the City of Long Beach, California. The Wilmington Field lies underneath and offshore the coastal city of Long Beach, California, roughly 20 miles south of the city of Los Angeles (Figure 1). Production is from four man-made islands in Long Beach Harbor and from one land location on Pier J close to the Long Beach docks.