A new approach to select multi-lateral well candidates using a fuzzy-logic based computer model

Due to the character of the original source materials and the nature of batch digitization, quality control issues may be present in this document. Please report any quality issues you encounter to digital@library.tamu.edu, referencing the URI of the item.Includes bibliographical references: p. 72-76.Issued also on microfiche from Lange Micrographics.Multi-Lateral technology is defined as the drilling and completion of more than one wellbore from a single "mother" hole. The benefits of having multiple boreholes in a single well include increased flow rates, increased reserves, lower production costs, and improved drainage patterns or efficiencies. Candidate selection for multi-lateral technology has not been standardized and few literature references exist that can help individuals plan a multi-lateral well. Multilateral well candidate selection is usually tied to the results of a detailed and complex reservoir analysis. In many cases, small and independent companies are reluctant to apply multi-lateral technology without conducting a detailed economic analysis. In this research, we have developed a new easy, simple and fast, yet technically sound, method to screen candidate wells for possible application of multi-lateral technology. The new screening method is based on the simulation of human thinking by using a fuzzy logic model. This fuzzy logic model was built based on the personal experiences of industry experts in multi-lateral technology, as well as existing case histories of applications of multi-lateral technology found in the literature. The new model determines the best type of primary well configuration, choosing from a vertical well, horizontal well or a multi-lateral well. If the model suggests a multi-lateral well as the most appropriate option, the model then determ-nines the best multi-lateral configuration, choosing from a dual-opposed completion, a planar completion or a stacked completion. The output from the model is the level of confidence that the selected well configuration will be a technical success, based on the knowledge and experience used to build the model. The model was validated with four successful cases of application of multi-lateral technology published in the literature. The multi-lateral fuzzy logic model can be used to analyze the possibilities of applying multi-lateral technology for specific reservoir situations, limited to oil, onshore reservoirs composed of a single type of matrix. The model, however, should not be relied upon as the only screening tool. Numerical reservoir and economic models must also be used to determine expected well performance and to compute detailed economic analysis of all possible options