Summary In high hydrogen sulfide (H2S) and high-pressure/high-temperature fields, the average run life of electric submersible pumps (ESPs) is limited to 3 years. Dismantle/inspection/failure-analysis (DIFA) results show that approximately 50% of ESP failures are directly or indirectly related to electrical-delivery problems concentrated approximately 200 ft in between the packer and the motor. This paper presents a collaborative research-and-development effort to develop and trial test a reliable-power-delivery system (RPDS) with the goal of extending the average ESP run life from the current 3 years to 10 years. The development focuses on improving reliabilities of key power-delivery components including packer penetrator, motor-lead-extension (MLE) cable, and cable connection to the motor. The design integrates learnings from advanced completion and subsea technology, and includes new concepts, features, and materials. Field-pressure-testable connections are implemented to ensure proper field-connections makeup. Factory testing incorporated a robust highly-accelerated-life-test (HALT) methodology to simulate a 10-year service life. Prototype components were designed, fabricated, and tested. These components were integrated and subjected to a rigorous system-integration test. After the comprehensive factory tests, a field-prototype system was built and installed in an offshore well. The system has been operated and exceeds the trial-test success criterion of a minimum 180-day run life. For years, ESP reliability has been a constant issue faced by the industry, with electrical problems at the center of many failure causes. This paper presents a completely new design approach to address this critical challenge. Field installation and testing show the potential of extended run life with this new power-delivery technology.

In high H2S and high pressure/temperature fields, the average run life of ESPs is still limited to 3 years. Dismantle Inspection Failure Analysis (DIFA) results show that around 50% of ESP failures are directly or indirectly related to electrical delivery problems concentrated in about 200 ft between the packer and the motor. This paper presents a collaborative R&D effort to develop and trial test a Reliable Power Delivery System (RPDS) with the goal of extending the average ESP run life from the current 3 years to 10 years. The development focuses on improving reliabilities of key power delivery components including packer penetrator, Motor-Lead-Extension (MLE) cable, and cable connection with the motor. The design integrates learnings from advanced completion and subsea technology, and includes new concepts, features and materials. Field pressure-testable connections are implemented to ensure proper field connections makeup. Factory testing incorporated a robust Highly Accelerated Life Test (HALT) methodology to simulate a ten-year service life. Prototype components were designed, fabricated and tested. These components were integrated and subjected to a rigorous system integration test. After the comprehensive factory tests, a field prototype system was built and installed in an offshore well. The system has been operated and exceeds the trial test successful criteria of minimum 180 days run-life. For years, engineers and companies have battled with ESP reliability, with electrical problems at the center of many failure causes. This paper shows the development and field trial of a new generation ESP power delivery technology with the potential of extended run life.

The following is an update to an earlier paper compiled and presented in April 1991 at the ESP roundtable held in Houston, Texas.This paper contains referenced categories of problems that have been encountered in field operations and the solutions that have been found to-the prokierns. The discussion for each problem/solution set is brief, but serves as an index to the particular reference, where more detail can be found. The discussion is restricted to field cases. Many excellent studies such as design techniques and recommended procedures are not covered since they are not in the context of a field study containing problems and solutions. Also, some field operational papers were not included if they presented identical information. This study was originally intended to be review of the field cases and a summary of various failures and their causes as a function of the conditions present. However, when beginning to review the papers in the literature, it became obvious that it is rare for a given paper to list detailed field conditions. In fact out of the fifty or so references examined here, only a few contained sufficient field condition data which would have allowed problems and solutions to be correlated to conditions. In addition to categorized and referenced problems and solutions, new innovations, products and operating techniques are presented. Summary of Problems and Their SolutionsBeginning at the surface, equipment and associated problems and solutions to these problems mentioned in the 105 paper bibliographies of the field cases will be presented. Some of the solutions will appear to be very obvious or simple, but the appearance of the problem and solution will allow the user to reference the paper where it originated and to read in further depth on the subject.

Intelligent completion technologies are becoming a popular tool in the oil companies' quest for increased oil recovery. These new technologies place greater demand for electrical power and data transmission from unmanned platforms. A balance between extension of offshore platform life, increased oil recovery, and increased lifecycle costs must be obtained. This paper provides technical concerns, solutions, economic comparisons, and installation considerations through a case history on the application of a unique low-kilowatt submersible power cable for the electrification of offshore unmanned platforms. Introduction An Oil and Gas Production Company based in Brunei would like to build a portfolio of opportunities for applying intelligent completion technologies to existing and future wells. Together, with the relevant business cases, identify some key wells for testing and learning from the technology. Intelligent completion technology facilities the integration of state of the art concepts in well engineering, downhole measurement, inflow performance / control and production system optimization. Intelligent completion technology strategies are applicable to different areas and are outlined as:Operating Philosophy: Minimum manning / zero intervention of routine operations.Production Philosophy: Optimum utilization process for gas lift optimization using downhole temperature and pressure measurement.Well Completion Philosophy: Inflow control and multilateral wells.Well Optimization: More horizontal wells with reduced wellhead jacket structural requirement, sequence optimization and dual lateral designs etc. Effective cost delivery of electrical power to small, lightweight, isolated and unmanned platforms has become important with the introduction of intelligent completion technology facilities. Table A, shows the existing platform's power and capacity, existing loading and the proposed additional intelligent completion technology facilities load. Traditional methods of providing power to offshore platforms centered around the use of solar power, small generators or traditional high-kilowatt sub-sea power cables. Solar Power Distribution System (SPDS) Brunei's climate makes solar power an obvious candidate for electrical supply. Platform Peragam's SPDS is rated at 400W, Iron Duke is 2200W and all other locations are 100W. Every 10W of power requires 1 m2 of space for installation of solar panel and batteries. Previous studies showed that SPDS is cost effective for power rating of up to 100W, beyond this, it becomes very expensive due to the requirement of larger space for solar panel and larger battery bank size. This option is considered here since most of the power requirement is marginally higher than the economicalrating of 100 W. Currently, both industrial and certified types are available in the market. The operational experience is poor as summarized below:Limited capacity for future load growth.Hindrance with rigging activities.Batteries disposal problems.Limited available deck space for installation of larger power system.Lower availabilityHigh OPEX. SOLAR Design: In general a Solar Battery System and Battery capacity are designed for the site ambient temperature and maximum number of consecutive no-sun days (insolation). For Brunei the batteries autonomy is 3 days based on a daily 20% battery depth of discharge (DoDFactor). The capacity of the battery at the end of the autonomy time shall not drop below 20% state of charge level.

Previously, many Oil and Gas Production Companies elected not to develop hydrogen sulfide (H2S) producing fields, particularly offshore, in exchange for sweeter crude projects. A narrow number of H2S field developments resulted in a limited number of publications with empirical data on Electrical Submersible Pump (ESP) reliability producing in high H2S partial pressure offshore fields. This paper summarizes ESP reliability lessons learned and solutions implemented from more than 500 ESPs producing across three carbonate field wells characterized by high H2S/CO2 partial pressures, reservoir pressure and production rates; low bubble point pressure and low to mid-level water cut. This paper utilizes ESP field observations and pull failure findings from over 200 Dismantle Inspection and Failure Analysis (DIFA) to confirm H2S behavior and root causes of electrical and mechanical failures within multiple ESP components. Moreover, H2S affects where ESPs were initially idle and exposed to H2S for one to two years either in static conditions or in naturally high rate flowing wells prior to commissioning are discussed. DIFA observations over a wide range of ESP runlife was instrumental in establishing the need for technologies to slow H2S movement across ESP components inclusive of a tandem seal section. Several motor seal sections have failed mechanically from H2S attack thereby requiring upgrade to high alloy metals, ceramic radial bearings and upgraded mechanical seals. Laboratory testing of failed conductor insulations retrieved during DIFA further exposed H2S methodology in creating electrical shorts. Systematic approaches were adopted to identify any unnecessary contributors such as power quality, operational practices or human error that may have facilitated H2S attack. Following the investigation and identification of unnecessary contributors; H2S scavengers were introduced into the seal section to slow H2S migration into the motor, lead sheathed motor lead extension (MLE) was upgraded with new H2S resistant insulation materials and design along with other new technologies that were trial tested to further improve ESP reliability and run life in H2S producing wells. ESP component failure tracking and runlife statistics spanning an eleven year period are shared with the reader to validate the success of H2S resistant ESP component upgrades. Finally, methodology in calculating and measuring impact of varying degrees of H2S partial pressure and temperature from three high and two low H2S partial pressure ESP fields are provided.