Improving Energy Efficiency in E&P Operations

Abstract

Abstract BP has been striving to minimise the greenhouse gas emissions from its operations for several years. Since most emissions come from the combustion of fuel in processing operations, improving energy efficiency is the key to better emissions performance. The paper describes the tools and processes that have been developed to improve energy management and shares lessons from practical experiences of performance improvement in new projects and existing E&P operations. In all cases, improving energy efficiency has delivered significant business benefits. Introduction In 2001 BP achieved the commitment it made 4 years earlier to reduce its GHG emissions by 10% by 2010. Its goal now is to stabilise emissions at this level by minimising the emissions associated with growth, continuing to reduce emissions from its operations and participating in the development and use of flexible mechanisms such as emissions trading. Within E&P operations the early successes in emissions reduction were largely associated with reducing hydrocarbon loss through flaring and venting. Now the focus is moving increasingly towards improving energy efficiency in E&P operations. This paper describes BP's experiences in generating value by exploiting technology, developing energy management processes and engaging people to drive improved energy and emissions performance in new and existing E&P operations. Energy Team An important first step was to set up a dedicated team in order to provide focus on energy efficiency and to develop and co-ordinate the improvement programme. Specialists from various parts of the company were established in the new group to provide a range of expertise and experience. Establishing The Baseline The starting point in any performance improvement programme is to understand the current situation, have a means to quantify the baseline and measure any changes from that position. Within BP, an internal protocol had already been established to estimate and report CO2 emissions and therefore it was a relatively simple matter to collate data on combustion sources and report energy and hydrocarbons consumed, flared and vented. Since that time there has been great progress in establishing a consistent methodology for greenhouse gas emissions estimation for the petroleum industry1 A robust baseline of energy consumed, flared and vented was established in 2001 and is broadly aligned with this methodology. This indicated that in BP operated assets the gross energy consumed and hydrocarbon loss from flaring and venting was over 320,000 boe per day of which 83% was energy consumed in processes. Measuring Energy Efficiency The measure of energy performance was defined in the form of "specific energy consumption", energy per unit of production. By expressing production in units of energy, this performance indicator can be expressed as a simple percentage, energy consumed as a percentage of exported production. Wherever possible true energy units such as GJ are used, however in most existing operations available data is in barrels of oil equivalent (boe). The indicator is unsatisfactory in a number of respects, in particular because it cannot be used fairly to compare performance between different assets since the measure takes no account of the work required to deliver production. This is illustrated in Appendix A which lists the energy, flaring and venting loss for the Business Units in the 2001 baseline. The most energy intensive asset is the Greater Prudoe Bay operation in Alaska which re-injects around 9 billion scfd at up 4,000psi using 2GW of fully loaded gas turbine driven compressors. By the standards of our industry this is a relatively efficient operation but its high thermodynamic efficiency is not reflected in the value of the performance indicator of 16% energy consumed as a percentage of production when compared with the Group average of 5.6%. Table 1 gives the summary 2001 baseline data for energy consumed, flared and vented in operated facilities.