Effective Analytical Approaches to Enhance Productivity of Low Producing Gas Wells

Abstract

Hydraulic fracturing is a widely used technology in the industry to enhance oil and gas production, particularly in tight formations. Tight gas and shale cannot sustain commercial production rates without fracturing. Although the technique has been used in the industry for many years and vast improvements have been made in upgrading fluid chemistry, proppant types, pump schedule sequence, and overall well completion system, a close evaluation is always required to ascertain that the fracturing has provided the level of productivity expected from the candidate well. Such evaluation and analysis will help improve and optimize the stimulation technique for any given reservoir and field conditions, address specific challenges in that area, and determine remedial plans on any well that did not show expected results in terms of productivity enhancement.Saudi Arabian gas wells are usually stimulated to enhance and sustain production. Wells drilled in the R-1 reservoir in Field-A, that exhibit low to moderate permeability, are routinely hydraulically fractured. Many of these wells produce a high, sustained rate after a successful stimulation treatment. Some others do not perform up to expectation as seen from the rate decline. This can be caused mainly by inefficient fracture treatments such as achieving short half-length, limited vertical coverage, and poor post-frac cleanup. A critical and intense work on numerous wells has been performed using available data from geology, open hole logs, cores, pressure transient tests, etc., to understand and quantify reservoir characteristics, fracture properties, and flow capacity of these wells to come up with plans to improve productivity. Such plans include remedial treatments such as refracturing, placing additional perforations in previous unperforated intervals, initiating hydraulic fractures in different layers, and sidetracking the well to change its trajectory and geometry to contact new producing intervals. This paper summarizes the well conditions, complete evaluation processes, and suggests remedial procedures for each well to ensure full potential.

The Key and the Countermeasures Research of Shale Gas Fracturing Technology

“…No gas flow was observed for the 40% of early borehole test in U.S., and 55% of the absolute open flow was without the industrial value; eventually fracturing horizontal well productivity can exceed 10 10 4 m 3 /d. Critical and intense work on numerous wells has been performed using available data from geology, loggings, cores, pressure transient, et al, to understand and quantify reservoir characteristics, fracturing properties, and flow capacity of wells to come up with plans to improve productivity [11].…”

Modified Approach for Reorientation Fracturing Propagation Trajectory Prediction

“…Re-fracturing, designed for oil/gas formations the secondary or more fracturing after initial hydraulic fracturing, is one of the most effective stimulation methods for low or even ultra-low permeability reservoirs exploitation during the late lifetime of the oil/gas wells, where the reorientation fracturing holds a high percentage [1]. With decades of development, re-fracturing plays an increasingly important role in oil/gas exploitation [2][3][4][5]. Unfortunately, not all wells taking re-fracturing stimulation technology make success or achieve the goals anticipated, which may mainly attributes to the lack of comprehension of re-fracturing mechanism in deep [6].…”