A Comprehensive Statistically-Based Method to Interpret Real-Time Flowing Well Measurements
Sponsoring Organization: Department of Energy
This project proposes to develop new methods for interpreting measurements in complex wells (horizontal, multilateral and multi-branching wells) to determine the profiles of oil, gas, and water entry. These methods are needed to take full advantage of "smart" well instrumentation, a technology that is rapidly evolving to provide the ability to continuously and permanently monitor downhole temperature, pressure, volumetric flow rate, and perhaps other fluid flow properties at many locations along a wellbore; and hence, to control and optimize well performance. This spatial and temporal measurement density is unprecedented in the oil industry, and offers the promise of revolutionary changes in the way complex wells are operated. However, the key to realizing the value of smart wells is the efficient and accurate interpretation of the raw data being acquired. Converting this raw information about wellbore conditions into the useful knowledge of the phase flow profiles is the primary goal of this project.
The specific objectives of the project are:
- Develop a model to predict temperature, pressure, and flow profiles in complex wells, including nominally horizontal laterals, variably-inclined build sections, wellbore junctions, each of which may have commingled fluids with different properties.
- Develop inverse methods to infer phase flow profiles (the distribution of oil, water, and gas inflow along a complex well) from continuously monitored data.
The general approach to the forward problem of predicting temperature, pressure and flow profiles is to apply mass and energy balances to the well system to model these parameters as functions of position and time. The problem to be solved is the following: given any arbitrary inflow profile for oil, water, and gas into any section of a complex well, what is the local temperature, pressure, and total flow rate at any location in such a well? We will include the fundamental thermodynamics of the fluids, incorporating modern three-phase equations of state into the forward problem.
The success of the proposed work in meeting the stated goals lies in finding a solution to the inverse problem of complex wellbore flow in smart wells - that is, given measurements of temperature, pressure, total flow rate, and perhaps other flow properties distributed along many locations of a complex well, and at numerous times, what is the profile of inflow of oil, water, and gas along the well at any time? We will seek a method that determines this profile of all phases from a multitude of measurements, while minimizing the global error in the interpretation using a statistical approach.
Larry W. Lake
Center for Petroleum and Geosystems Engineering
1 University Station C0304
The University of Texas at Austin
Austin, Texas 78712-0228
Phone: (512) 471-8233 FAX: (512) 471-9605
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