Chirag field was the first of three fields put into production in the Azeri -Chirag -Guneshli (ACG) megastructure, located in the Azeri sector of the Caspian Sea and operated by BP on behalf of Azerbaijan International Operating Company (AIOC). Production commenced in late 1997 after completion of the Chirag A01T1 well. A number of different sandface completion types have been installed in Chirag injectors and producers during the Chirag Early Oil Project (EOP), and significant data have been collected to evaluate the performance of each completion type. Completion types include cased and perforated, open hole gravel packs (OHGP) using wire-wrapped, pre-packed and alternate path (shunttube) screen technology, stand-alone porous metal fiber premium screens, and expandable screens. To date, 29 completions have been installed in 19 of 24 available well slots in primary and sidetrack wells.Many of the producing wells are equipped with permanent downhole pressure-temperature gauges, the flowlines are equipped with acoustic sand detection devices, and an active separator production test and surveillance program has resulted in a quality data set to evaluate completion performance under initial "dry oil" (water free) conditions, and upon the onset of produced water. This quality data set has greatly assisted the completions performance analysis, which has helped shape completion decisions and technology requirements for full field development.The paper will review the completion evolution in Chirag field, the relative performance of completion types over a broad range of indicators, and will include a discussion about measures taken to improve open-hole gravel pack performance from a reservoir damage perspective, with a focus on producers.
TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractMany of the recently discovered reservoirs in deepwater/subsea environments are prime candidates for horizontal open-hole gravel packs. Presence of multiple reactive shale breaks and penetration of different sand bodies along these holes introduce a formidable challenge for selection of proper carrier fluids, considering that most of these wells require oilbased (OB) drilling fluids.Various procedures were practiced for gravel-packing wells drilled with OB fluids, most utilizing water-based (WB) carrier fluids. Primary concern in using WB carrier fluids is the destabilization of the shales.If the displacements to WB fluids are performed prior to running in hole with the sandface completion assembly, inability to run the screen assembly to target zone is the risk. Consequently, operators were forced to use a two-step process, whereby a predrilled liner is run in hole in OB fluid environment, followed by displacements to WB fluids and gravel-packing with WB fluids. This approach introduces additional rig time and increases completion costs.If the displacements to WB fluids are performed after running in hole with completion assembly, primary challenge is the prevention of screen plugging. This necessitates a comparison of the benefits and risks of displacements to solids-free oil-based fluids and conditioning of the OB drilling fluid, considering logistics.An additional consideration in gravel packing with WB fluids in reactive-shale environments is the risk of intermixing of gravel with shales, thus reduced gravel-pack permeability. Various approaches may be taken to minimize this risk. The type of carrier fluid must also be kept in mind from a formation and gravel pack damage standpoints, should losses be experienced during gravel packing.Another approach in reactive shale environments is to use an oil-based carrier fluid and avoid exposure of the open hole to WB fluids both prior to and during gravel packing. This approach, practiced in two applications, also has its limitations.In this paper, a critical review of gravel-packing practices in oil-based drilling environments is provided, along with some of the recent developments and recommendations for future applications based on lessons learned from earlier practices.
Veterans of the conflicts in Iraq and Afghanistan often experience moral injury as an ambiguous sense of guilt or deep confusion or annihilation of a sense of what is good and right. Augustine argued that as personal agents, our willing follows that which we desire—the problem is that our desires are externally and internally distorted and our willing thus follows goods that are twisted and false. I argue that an Augustinian framework of human willing in pursuit of distorted goods holds a great deal of explanatory power in terms of the pathology of human violence and the phenomenon of moral injury in combat veterans. As several prominent psychological studies suggest, evolutionary, societal, and cultural forces condition our capacity to make critical moral decisions. Those studying moral injury in combatants have observed the profound guilt that eventually results from their participation in acts of violence and even in support of missions whose moral “good” they come to question. An Augustinian framework recognizes both the power of these external forces and the distortable nature of our own moral values and therefore allows us to locate moral injury in the realm of systemic, widespread societal and cultural problems. This definition allows the experience of differing levels of participation in wartime violence from “front-line combat” to support missions to be understood as valid experiences of moral injury while simultaneously recognizing that one’s active agency is required in order to experience moral injury. Further, this framework may resonate with veterans who experience hopelessness as a result of reflection on the malleability of human willing and its profound vulnerability to outside forces.
Through-tubing bridge plug (TTBP) water shut-off (WSO) workovers in the October Field have resulted in an average incremental initial production increase of 2500 bopd per job. Average water cut (WC) was reduced from 55% to 16%. Seventy-eight WSO workovers have been completed since December 1991. Technical and economic success approach 90%. Just under $4.8 million dollars has been spent for an average cost of $61,500 per job. Costs paid out in less than two days using a normalized $13 per barrel crude price. Based on results achieved during the past 4.5 years, these WSO workovers establish the October Field as a notable and on-going case history for lower zone water control. Water production from the October Field has gradually increased during the past decade. As a result, steeper production declines and gas lift operational problems developed. Based on reservoir characteristics, lower zone water was isolated using TTBP's conveyed by way of portable mast electric line units. A dump bailer was used to place a 14 foot cement cap over the TTBP to provide a permanent pressure seal. After a 24-hour shut in cement cure period, wells were almost always returned to production at a significantly higher oil rate and dramatically reduced WC. The cost of a rigless TTBP WSO workover is much less than conventional rig deployed WSO work which averaged over $500,000 per job. Prior to December 1991, rig WSO's were the only method used in the October Field. Hence, rigless WSO workovers have become vital for cost control. Rigless WSO work has also become a useful reservoir management tool for maximizing oil production and minimizing water production thereby conserving reservoir energy and optimizing lift gas. Introduction The October Field is located offshore in the Gulf of Suez (GOS) approximately 200 miles southeast of Cairo and 70 miles north of the operating base in Ras Shukheir, Egypt (Figure 1). The October Field area is the largest of seven major producing areas in the GOS operated by the Gulf of Suez Petroleum Company (GUPCO); a joint venture between Amoco Egypt Oil Company and the Egyptian General Petroleum Corporation. Combined GUPCO GOS production averaged 365,000 bopd during early 1996. Gas lift is the most widely used form of artificial lift. Original oil in place (OOIP) for all fields approached 10 billion barrels by 1996.
TX 75083-3836, U.S.A., fax 01-972-952-9435.
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