Workflow for Probabilistic Resource Estimation: Jafurah Basin Case Study (Saudi Arabia)

Abstract

This study provides a workflow and preliminary estimations of the estimated ultimate recovery (EUR) volumes for natural gas and condensate liquids in the Tuwaiq Mountain Formation, the principal target in the Jafurah Field development project in Saudi Arabia. The strategic need for the field development is reviewed and the field characteristics are outlined based on public data sources complemented with data from analogous reservoirs. The target zone in the Jafurah Basin is a carbonaceous shale, being developed with up to 10,000-ft-long multistage-fractured laterals with 30 ft perforation cluster spacing and an assumed typical 1250 ft well spacing. The field will come on stream in 2024, when the gas-gathering pipeline system, natural gas processing plant, and underground gas storage facilities will all be in place. The range of uncertainties in the key reservoir parameters is taken into account to estimate preliminary EUR volumes (P90, P50, and P10) for both gas and condensates. Based on the present and prior EUR estimations, it can be concluded that the Jafurah Basin comprises one of the largest unconventional field development projects outside of North America.

The Impact of Formation Anisotropy and Stresses on Fractural Geometry—A Case Study in Jafurah’s Tuwaiq Mountain Formation (TMF), Saudi Arabia

“…SEM images revealed a well-connected organic pore system in the matrix of the TMF with interconnected porosity averages of around 10%. The pores were mostly irregular polygonal to spherical, with pore sizes of mainly less than 1 µm; the remaining fraction had micropores greater than 1 µm [25,27].…”

“…The liquid-rich Jafurah shale play is located east of the greater Ghawar field, which is the world's largest conventional oil field located in the eastern region of Saudi Arabia (see Figure 1) [23,24]. On the basis of exploration and appraisal programs, the ultimate recovery of natural gas and liquids from the play is estimated to be around 200 trillion cubic ft equivalent (tcfe), and the first commercial production is to start in 2025 [25,26]. On the basis of a petrophysical evaluation in the Jafurah basin, the primary target formation is the Jurassic Tuwaiq Mountain (TMF), which is the principal rock source of the prolific Arab-D carbonate reservoir [25,26].…”

“…On the basis of exploration and appraisal programs, the ultimate recovery of natural gas and liquids from the play is estimated to be around 200 trillion cubic ft equivalent (tcfe), and the first commercial production is to start in 2025 [25,26]. On the basis of a petrophysical evaluation in the Jafurah basin, the primary target formation is the Jurassic Tuwaiq Mountain (TMF), which is the principal rock source of the prolific Arab-D carbonate reservoir [25,26]. TMF exhibits exceptional unconventional gas characteristics, such as a high total organic content (TOC) and low clay content, and it is in the proper maturity window for oil and gas generation.…”

“…TMF exhibits exceptional unconventional gas characteristics, such as a high total organic content (TOC) and low clay content, and it is in the proper maturity window for oil and gas generation. The thickness of the TMF interval ranges from 110 to 150 ft across the Jafurah basin [23][24][25].…”

Applications of Differential Effective Medium (DEM)-Driven Correlations to Estimate Elastic Properties of Jafurah Tuwaiq Mountain Formation (TMF)

“…The Jafurah liquid-rich shale play is located east of the greater Ghawar field, which is the world's largest conventional oil field located in the eastern region of Saudi Arabia (see Figure 2) [18,19]. Based on exploration and appraisal programs, the ultimate recovery of the natural gas and liquids from the play is estimated to be around 200 trillion cubic feet equivalent (tcfe), and the first commercial production is scheduled to start in 2025 [20,21]. Based on a petrophysical evaluation of the Jafurah basin, our primary target formation is the Jurassic Tuwaiq Mountain (TMF) formation, which is the principal source rock of the prolific Arab-D carbonate reservoir, as shown in Figure 3 [20,21].…”