It is well known that primary depletion using horizontal wells with multistage fracturing can only produce a few present of the oil in shale reservoirs. The question how to produce the remaining oil needs to be answered sooner or later. Probably answering this question becomes more important in the current low oil price, as high-cost drilling, fracturing and completion have to be minimized. Considering different enhanced oil recovery methods, gas injection is probably most feasible method. The huff-n-puff method consists of three stages: huff, soak, and puff. Steam is injected into the well (huff), allowed to sit and heat up the reserve (soak), and then the hot oil is pumped out of the well (puff). Compared to gas flooding and other other enhanced oil recovery methods, huff-n-puff has more operation parameters to optimize so that liquid oil production can be maximized. This technology tends to enhance the optimum huff and puff times, number of cycles and soaking time under practical operation and reservoir conditions.
Reference Number: D-1211
Enhanced oil recovery (EOR)
Any company who produce shale resources
Features, Benefits & Advantages:
Use of existing well bores to improve remaining oil production
Improve liquid oil recovery in shale oil reservoirs
A U.S Provisional Patent Application was filed 12/07/15.
This technology has been tested and simulated with a series of physical, well-condition models to determine if the principles hold up, and it does. The principles however, still need to be applied to actual shale oil reservoirs.
James J. Sheng, Ph.D, Associate Professor, Petroleum Engineering Department, Texas Tech University, lubbock TX
Keywords: Optimization, huff-n-puff, soak, cycle, EOR, IOR, shale