油气井完井决策资源综合评价-矿物学、声、与NMR的整合.ppt

The Problem Well1.75 MMscf/d Q: Why did the fractures propagate differently? A: Perforation scheme. Haynesville Well A Target Perforations in Siliceous Intervals 4.5 MMscf/d Well B 1.75 MMscf/d Well A Well B has perforations aligned with siliceous facies (yellow lithology). Well A has perforations aligned with the clay-rich facies (grey lithology). Siliceous Facies Have More Natural Fractures Siliceous facies are identified primarily by their abundant quartz content. The brittleness of the quartz allows hydraulic fractures in siliceous facies to grow further than in the clay. Partially open quartz-filled micro-fracture. Calcite filled fractures are visible on the macro-scale. ≈ 4 inches Siliceous Clay-rich Partially Open Fractures Reduce Pb The measured breakdown pressure in Well B matches the predicted pressure for an open fracture system. In well A the measured pressure matches the predicted pressure for a formation with no natural fractures. Integration: The Key to Delivering a Gas Shale Solution for Effective Reservoir Characterization Favorable Fracture Zones or Intervals for Horizontal Drilling- Lowest Minimum Horizontal Stress Fracture Barriers-Highest Minimum Horizontal Stress Fracture Attenuators: Clay Compositions and Amounts that cause fracture embedment problems Jacobi et al. , SPE, 2009 And now for something completely different… Permeability – Using Mineralogy k = perm in mD Af = 4.9 + 2* max feldspar Bi = surface area coefficient Mi = weight fraction mineral from Herron, SPWLA, 1987 Cozeny-Karman relates k to surface area Herron equation (1987) I used these constants and the Herron equation with NMR porosity where available. Woodford Shale example Core results Blue dots are derived from Herron, core XRD, and core porosity. Pink dots are from the fit equation in the other graph on this slide. Barnett and Haynesville k (core) nD k (Herron) nD 19 3 11 11 16 7 23 1 11 40 5 1 There is not enough variation to plot. But all are consistent. Haynesville