The Risha field is located in the North East region of the Hashemite Kingdom of Jordan approximately 370 km from Amman and is bordered by Iraq to the East, Syria to the North and Saudi Arabia to the South. Risha was discovered in 1987 and production started in 1989. The field consists of a predominantly tight gas reservoir but seismic and core data indicate the presence of faults and fractures. The Risha reservoir is late Ordovician, and is interpreted as a marine proglacial outwash fan setting. 45 wells have been drilled to date with mixed success and only 15 wells demonstrated some degree of production capacity. Historic well performance trends indicate a range of well types with some illustrating high initial rates, recoverable volume, and slow decline without need for stimulation. Others suffered from very low rates and sharp declines even after undergoing hydraulic fracturing. To date, high rate and recovery wells have been associated with fracture presence making fracture the key reservoir drive mechanism.
This paper attempts to analyze other potential reasons and factors causing well deliverability variation to date. It discusses the integrated approach followed to categorize the Risha rock types and determine whether they could be linked to historic reservoir performance. In this paper the reservoir units were loosely grouped according to petrophysical cutoffs, based on gamma ray, and compared with core data. The defined rock types along with well control were used to create a 3D simulation to model the rock quality variability and match the production and pressure history, with the ultimate aim of trying to understand if history performance is a reliable indicator of future behaviour.