The SPE has split the former "Management & Information" technical discipline into two new technical discplines:
- Data Science & Engineering Analytics
The SPE has split the former "Management & Information" technical discipline into two new technical discplines:
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This course is designed to give trainees an overview of various artificial lift solutions and related production optimization concepts. After introducing participants to the need for an artificial lift system, training will focus on each of the following lift methods: Gas lift, Reciprocating Rod Lift, Progressing Cavity Pumping, Hydraulic Pumping, Electrical Submersible Pumping, Plunger and Capillary System. For each lift type, the course covers main components, application envelope, relative strengths and weaknesses. Animations, field cases, and example-calculations are used to reinforce concepts. A unique feature of this course is discussion on digital oil field as applicable to lift optimization.
Khadav, Sandeep (Cairn Oil & Gas, a vertical of Vedanta Limited) | Agarwal, Shubham (Cairn Oil & Gas, a vertical of Vedanta Limited) | Kumar, Piyush (Cairn Oil & Gas, a vertical of Vedanta Limited) | Pandey, Nimish (Cairn Oil & Gas, a vertical of Vedanta Limited) | Parasher, Arunabh (Cairn Oil & Gas, a vertical of Vedanta Limited) | Kumar, Sanjeev (Cairn Oil & Gas, a vertical of Vedanta Limited) | Agarwal, Vinay (Cairn Oil & Gas, a vertical of Vedanta Limited) | Tiwari, Shobhit (Cairn Oil & Gas, a vertical of Vedanta Limited)
Abstract Bhagyam is a shallow onshore field in the northwestern region of India developed by Cairn Oil & Gas, a vertical of Vedanta Limited in two different phases with over 106 oil-producers with deviations as high as 70° and Dog Leg Severity (DLS) up to 7 deg/30m. Rod driven Progressive Cavity Pumps (PCP) were selected as the primary mode of artificial lift. The produced fluid properties which included high wax content and variable fluid viscosity ranging up to 250 cP were the main drivers in the selection of PCPs. A total of 250 unique installations of PCP systems have been completed in over 100 wells. These systems have accumulated a cumulative run-time of over 150,000 days over a total period of more than 2550 days from first installation, with an average tubing-pump system run-life of 600 days. A major disadvantage of using a rod driven artificial lift system is metal to metal wear between rod and the tubing during operation. This metal wear in rod and tubing results in string failure, increasing costly well interventions and increased system downtime. This paper will demonstrate through specific case studies how pump operating parameters and well design were optimized over time to reduce well interventions and operating expenditures (OPEX). A centralized data base with real time data configured with a predictive analytical model and automated performance analyzer have enhanced PCP monitoring and troubleshooting. Predictive modelling has improved preventative maintenance such as preemptive rod change outs which greatly reduced the number of rod failures increasing system uptime. In conjunction with joint industry program, detailed root-cause analysis supported with Dismantle Inspection and Failure Analysis (DIFA) laid the foundation for operational and design improvements in PCP operated wells. Some of the recent improvements employed in system design for PCP operated wells are: Installation of through tubing PCP on an insertable anchor/pump sitting nipple Installation of packer with completion string Use of peened rods with molded guides Snap-on and spin thru guided rods Installation of externally flushed hollow rod string Replacement of conventional vam top tubing with boronized tubing Installation of high volume PCPs.
Poptani, R. V. (Cairn India Limited) | Mishra, L.. (Cairn India Limited) | Gupta, A. K. (Cairn India Limited) | Saurav, S.. (Cairn India Limited) | Singh, C. K. (Cairn India Limited) | Agrawal, N.. (Cairn India Limited) | Patel, N.. (Cairn India Limited) | Hammond, P.. (Cairn India Limited)
Abstract Bhagyam field is located in the prolific Northern Barmer Basin in Rajasthan, India. It has nearly 110 producers and some of these wells have limited pressure support and are geologically distinct from the rest of the field. These wells are flowed intermittently according to a pre-defined cycle based on flowing bottom-hole pressures to optimise their production. Various stimulations have been attempted to increase near wellbore productivity. However, these have largely been unsuccessful. A further restriction is posed by the completion of these wells on Progressive Cavity Pumps (PCPs) as the artificial lift method which inhibits the use of acids and aromatic compounds. This paper illustrates the successful trial of surfactant stimulation in increasing the productivity of these wells. Surfactants were considered as an alternative technique for stimulation as they pose no harm to the PCP elastomers. In addition to this, they help alter the wettability in the mixed wet to oil wet reservoir of Bhagyam field. The stimulations were designed to get the maximum penetration and were bull-headed from surface. This paper also discusses the unsuccessful stimulations carried out prior to field trial of surfactant stimulations and the studies done in the field to understand the damage mechanism behind low productivity/productivity decline. More than 10 wells (both low PI wells and intermittently flowing wells) have been successfully stimulated with surfactants till date in the field and have helped substantially in sustaining the overall field production.
Abstract This paper provides the design and operating considerations for Progressive Cavity Pumping (PCP) systems in Coal Bed Methane (CBM) wells based on field experience and illustrates their optimization with case studies of C-Fer software simulation and field trial. The challenge is to effectively lift water throughout the CBM well life with the same PCP system while accommodating pressure head increments and flow rate decrements with time. This paper presents a novel idea to optimize PCP system at different stages of CBM well life with minimal cost implications to the company. The major inputs for artificial lift design are seam depth and well productivity, while PCP head and flow rate, down-hole string sizing and motor sizing are the required outputs. To take a case study of PCP system optimization, we have Well – A, where the bottom perforation is at 600 m and the water production is expected to start with a peak of 150 m/day at 100 m water level and reach 100 m/day at 600 m water level in about 10 months. The authors chose a system with flow capacity of 76 CMD at 100 RPM and lift capacity greater than 800 m. Tubing size of 2.875″ is chosen and sucker rod size of 1″ is chosen. The surface motor of 22 kW is selected based on the maximum power required by the PCP system at the maximum lift condition. The process of selection is depicted clearly in this paper. Although, the PCP system is designed as per the design considerations, the maximum RPM in the initial CBM well life may be limited by the pulley ratio (driven pulley diameter: driving pulley diameter) while the torque imparting capability of the motor at later stages may be limited by the motor frequency at the later stages of the well life. Hence, simulations for different run scenarios (water levels and flow rates) were done in C-Fer PC-Pump software for two cases taking Pulley Ratio as 4.74 and 6.22. The authors have presented trends comparing important parameters namely Fluid Level-Surface Motor loading, Fluid Level-Maximum Rod Torque and Fluid Flow Rate-Pump Speed. Based on the interpretation of these results, it was decided to experiment with two different driving pulleys for changing the pulley ratio during the well life to optimize the PCP system instead of upsizing the motor. This field trial was successfully conducted in Well – B and the parameters and the results are clearly depicted in the paper. Changing the pulley ratio over CBM well life will fulfill the torque and power requirements at the required pump RPM with significant cost savings by eliminating the need to install a new motor.
Abstract Progressive Cavity Pumps (PCPs), if properly sized, can greatly improve a well's deliverability and run-life. As a result, PCP sizing for a large number of wells can be instrumental in a production optimization program. This paper presents a quick look methodology adopted in the Bhagyam field to better understand PCP system performance and to accurately predict pump deliverability under a wide range of downhole conditions for more than a hundred wells. Using nodal analysis, this paper presents the procedure used to select optimum pump size and well fluid rates from well inflow and outflow performance. The paper also presents a correction factor for the effect of viscosity on pump performance and uses the corrected pump performance curves to model the expected liquid rate from a well. The solutions obtained with the analyses have been validated against actual Bhagyam well test data and have proved to be fairly consistent. This procedure has not only been a useful tool for pump selection and performance monitoring but has also made a significant business impact in terms of incremental oil gain.The methodology quickly provides reasonably accurate solutions for pump selection and allows evaluation of real time pump parameters to optimize PCP under varying field conditions.
Abstract Bhagyam field is an onshore, shallow field containing light sweet oil (27° API) with low Gas Oil Ratio (GOR) (~100 scf/stb). The crude has ~30% wax content with moderate insitu oil viscosity of ~ 50–250 centipoise (cP) with wax appearance temperature (WAT) ~2° C lower than the reservoir temperature of 53° C. With water production, it was initially expected that viscosity of production fluid will rise upto 3000 cP due to emulsification. Rod driven Progressing Cavity Pump (PCP) system was selected as artificial lift for the field development considering low GOR and relatively high fluid viscosity. To ensure flow assurance of the high WAT crude, various methods such as annular hot water circulation, heater cable, vacuum insulated tubing (VIT) etc were considered. Based on the analogue Mangala field, which is located in the same license area, it was decided to utilize annular hot water circulation as the downhole heating methodology as it provided a significant completion design similarity with previous installation and operational experience. This completion involves running Colied Tubing (CT) clamped to the main production tubing as a secondary string. The main production tubing with PCP stator is stabbed in a production packer for downhole isolation.Hot water is circulated at 85° C down the coil taking returns through the annulus. This arrangement ensures temperature of the fluid inside the main production tubing is maintained higher than the WAT at all times. In the 1 phase of field development, wells completed with PCP and have been successfully operating for ~ 2 years meeting requirement of flow assurance & PCP run life. However, PCP efficiency was lower in high GOR wells, as downhole gas separation was not possible. For the 2 phase of development, alternate completion designs which can mitigate the downhole flow assurance challenges and at the same time open up the annulus similar to a conventional PCP application were considered and finally hollow rod driven PCP design was selected as the most suitable method. The paper details PCP application in Bhagyam field during the first two phases of development, installation & operating practices, lessons learnt & overall system performance.