Collapse Analysis of Screens Used in Horizontal Open Hole Gravel Pack Completion

Abstract

Global increase in energy demand and the lack of opportunities onshore or in shallow waters are driving production of hydrocarbons towards deep and ultra deep-water basins, where reservoirs are usually formed by weak and unconsolidated sandstones that require sand control methods to prevent damage in surface and subsurface equipments. Guidelines to select sand control systems are primarily based on sand exclusion, seeking to optimize balance between oil rate and fines production. Another aspect, often overlooked, is collapse strength of the system formed by the sand control equipment and the formation itself, subjected to mechanical loadings that change during life of the well. This contribution presents a method to evaluate collapse strength of sand control systems taking into account mechanical interaction between the formation and sand control screens. Elastoplastic models are used to represent granular materials. The most usual sand control system was studied: gravel pack with premium screens. A model to describe contact between granular materials (gravel and formation) and soil-pipe interaction is proposed. Results demonstrate that perforated base pipes used in premium screens may be oversized for applications under regular operating conditions. Introduction From the 80s the offshore world oil production surpassed the 25% of the total volume produced and became a new frontier in the search of non-renewable energy sources. Since then, the continuous increase of oil demand and the high oil prices allowed for the development of basins in more challenging scenarios. In the last years, most part of oil and gas reserves which have been discovered are found in deep and ultra deep water in Gulf of México (GoM), Brazil, West of Africa and Austrália in a complex environment comprising turbiditic reservoir, non-consolidated sandstones, reative shales, low fracture gradient and high porosity and permeability reservoirs. These are a great challenge to the development explotation projects (Bianco, 2007). In this scenario, it is mandatory to develop alternatives to sand control to build high rate wells, and the Open Hole Horizontal Gravel Packing (OHHGP) constitutes one of the most used techniques for solid control in horizontal wells. In Brazil more than 200 wells have been built by means of this technique, and it is one of the main alternatives used by Petrobras for offshore well completion. During the sand control design and selection, the aim is to obtain an optimal relation between the oil rate and the solid production in terms of the formation granulometry. However, the loading imposed on sand control system by formation has not been considered in the OHHGP design.

Study on the extension limit model of a horizontal well with supercritical carbon dioxide drilling

“…Second, the collapse pressure and fracture pressure in a horizontal well with supercritical carbon dioxide drilling were studied. Currently, the immersion effect of supercritical carbon dioxide on the physical property of rocks has been considered, and the mechanics variation of the rock surrounding a wellbore with a different azimuth angle, deviation angle, and bedding dip angle can be obtained through literature review . Therefore, the collapse pressure and fracture pressure in a horizontal well with supercritical carbon dioxide drilling can be calculated.…”