Oil production in the United States (US) increased rapidly in the last decade due to the extensive development of tight-oil resources like Permian, Eagle Ford and Bakken. Most of these resources benefit from being in a source rock or in a close proximity to a source rock and they can be called here source-related tight-oil resources. There are also non-source tight-oil resources, such as the vast tight-carbonate resources in the Middle East. In this paper, a detailed characterization of Middle East non-source tight-oil carbonates is presented and compared to source-related tight-oil resources and their development potential is demonstrated through numerical simulation.
A conceptual 2D commercial simulation model is used to assess the factors affecting the development of non-source tight-oil formations. The model is capable of simulating the effect of key parameters on production from tight naturally fractured reservoirs with vertical and fractured horizontal wells. Improved recovery options, such as waterflooding and gas injection, can also be evaluated under different reservoir characteristics.
Tight-carbonate reservoirs possess the structural characteristics of conventional reservoirs while sharing the low-permeability, natural-fracture, and small-scale heterogeneity attributes of source-related, tight-oil resources. Moreover, they pose their unique challenges such as scale-dependent variability of their properties, sensitivity to acid fluids, the need for improved recovery techniques and complex wetting properties. The simulation results show that these formations are more sensitive to natural fractures compared to high permeability reservoirs and fractured horizontal wells are an essential technology. The viability of improved recovery techniques, such as waterflooding and gas injection, in these formations may be a critical factor for development decisions.
Most of the resource development strategies that are available in the literature are focusing on either conventional high permeability reservoirs or unconventional source-related resources. Due to the success of the technologies used in the US unconventional plays, development potential of the non-source tight-oil formations has emerged as an industry interest. This paper sheds light on the development of another type of oil resource which is abundant in the Middle East and around the world.