Horizontal wells have dominated conventional wells because of their increased production rates, improved recovery efficiency, increased reservoir drainage area, and delayed gas and water coning. However, nonuniform-flow profiles can result in premature water/ gas production, loss of production and reserves, and a decrease in profitability, which will shorten the life, and defeat the purpose, of a horizontal well.This paper describes a new production-technology system that will optimize production, delay water/gas coning, eliminate/ minimize annular flow, and ensure uniform inflow along the lateral at the cost of a minute pressure drop in long, high-rate horizontal wells. A case history is presented in which this production technology, combined with sand-control technology, has resulted in significant savings for the operator and improved production in offshore horizontal oil wells.

TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractHorizontal wells on a global basis continue to serve as a primary well type for improving recovery efficiency, increasing reservoir drainage area, delaying water and gas coning, and increasing production rate. However, in longer, highly deviated and horizontal wells, non-uniform flow profiles can result in premature water or gas breakthrough, screen plugging, and erosion which can shorten well life and decrease well profitability. This paper describes historical and new applications of a proven production technology system that optimizes production, delays water and gas coning, minimizes annular flow to prevent erosion, and ensures uniform inflow along the lateral at the cost of a minimized pressure drop in high-rate horizontal wells. Global applications to date of this system include sandstone and carbonate formations as well as light weight and heavy oil. The case histories presented include the Norwegian Sector of the North Sea and carbonate formations of Saudi Arabia, where this production technology, combined with sand control technology, has resulted in significant savings for the operator and improved production in horizontal oil wells.

No abstract

fax 01-972-952-9435. AbstractHorizontal wells have dominated the conventional wells due to their increased production rates, improved recovery efficiency, increased reservoir drainage area, and delayed gas and water coning. However, non-uniform flow profiles can result in premature water / gas production, loss of production and reserves, and decrease in profitability, which will shorten the life, and defeat the purpose of a horizontal well. This paper will describe a new production technology system that will optimize production, delay water / gas coning, eliminate / minimize annular flow, and ensure uniform inflow along the lateral at the cost of a minute pressure drop in long, high-rate horizontal wells. Case history will be presented from Saudi Aramco, where this production technology, combined with sand control technology, has resulted in significant saving for the operator, and improved production in horizontal offshore oil wells.

One of the limiting factors affecting the length of horizontals wells has been the effective management of reservoir sweep with regards to wellbore influx. The added benefit of greater reservoir contact is met with increased differential drawdown across the well length and greater tendency to cut across heterogeneous formation with varying permeability. For many years, inflow control devices (ICDs) which restrict flow by creating additional pressure have been used to mitigate this problem. They are, however, passive in nature and once installed cannot be adjusted. In the event of water or gas breaking through in an oil well the disadvantage of the passive ICD become evident as the well would be quickly overtaken by the breaking fluid since they are usually designed to choke oil. Autonomous ICDs (AICDs) are, however, self-regulating and are classed as active. Unlike its passive counterpart, which produces greater choking for higher density fluids, they in addition to choking oil, choke water and gas more readily. This prevents the well from being flooded when unwanted fluids break through therefore providing the advantage of being able to even out inflow into the well and in addition, choke compartments producing unwanted fluids leading to greater recovery, lower water cut and gas production. This paper provides a comprehensive model of the autonomous ICD and goes further to show how this can be applied to modelling its influence on inflow distribution in a completed well system. The model is validated by comparing results obtained with tests carried out in a flow loop. A comparison of results obtained from the autonomous ICD and passive one is also shown to highlight the effectiveness of the autonomous ICD in flow regulation over the passive ICD.