Wafra Field

The objective of this study was to look at factors that can affect a temperature log and steps that can be taken to improve temperature-measurement accuracy. This paper covers the staged field-development methodology, including analysis and evaluation of various development concepts, that enabled the company to optimize both completion design and artificial-lift selection, reducing downtime and lowering operating costs by nearly 50%. The First Eocene is a multibillion-barrel heavy-oil carbonate reservoir in the Wafra field, located in the Partitioned Zone between Saudi Arabia and Kuwait. After more than 60 years of primary production, expected recovery is low and provides a good target for enhanced-oil-recovery processes.

The world’s largest oil producer has awarded $18 billion in engineering, procurement, and construction contracts as part of its Marjan and Berri expansion projects. The deal will bolster Arabian Drilling Company’s fleet to 67 rigs across the Middle East and North Africa. Ghawar vs. Permian Basin: Is There Even a Comparison? While some try to put the two enormous oil producers toe-to-toe, the best thing to do might be to understand why they are different. Take a quick look at some of the data points shaping upstream headlines and the movement of oil supplies around the world.

This paper introduces a new core-analysis work flow for determining resistivity index (RI), formation factor (FF), and other petrophysical properties directly from an as-received (AR) set of core samples. In this paper, the authors discuss the characterization process for GR tools and how they behave in boreholes different from the one used in the University of Houston (UH) GR characterization pit. This paper discusses a study undertaken to gain better understanding of nuclear magnetic resonance (NMR) characteristics of volcanic reservoirs with different lithologies. Formation evaluation drew special attention at the 2019 International Petroleum Technology Conference Education Week in Beijing, 24–28 March 2019. The student team that worked on Integrated Formation Evaluation for Resources Exploration and Reservoir Delineation won the first-place award. The first subsea multiphase boosting system was installed in 1994. Since then, it has grown into a technology with a global track record. A new enabling technology known as electrically heat-traced flowline (EHTF) will be used to enable system startup and shutdown and to maintain production fluids outside of the hydrate envelope during steady-state operation. This study incorporates previous learnings, as well as globally collected data, to develop a strategy that can be used to help implement an industry-specific mental health program. The value of hidden-danger data stored in text can be revealed through an approach that can help sort and interpret information in an ordered way not used previously in safety management. This paper highlights the results of a test campaign for a tool designed to predict the short-term trends of energy-efficiency indices and optimal management of a production plant. This paper presents the recent expansion of UNFC guidance to cover social and environmental effects and the further transformation of the system to make it a valuable tool in resource management for governments and businesses.

The strategy supports the Maximise Economic Recovery from UK Oil & Gas Strategy and Vision 2035, whose goal is to achieve £140 billion additional gross revenue from UKCS production by that time. The projects are designed to reduce technical risks in enhanced oil recovery and expand application of EOR methods in conventional and unconventional reservoirs. In recent years, some effort has been made to use EOR techniques, particularly CO2 injection, to extract additional oil and gas from unconventional resources. This has the potential to change the dynamics (again) of oil production from these tight and difficult reservoirs. One of my best moments is to have made the technical case for polymer flooding and to see the fruits of this several decades later.

The fourth industrial revolution is taking the oil and gas business by storm. Many companies have increased resources for big-data analytics and machine learning. Though no one sees physical oilfield services as in decline, development in these areas may take a back seat to artificial intelligence. This paper covers the staged field-development methodology, including analysis and evaluation of various development concepts, that enabled the company to optimize both completion design and artificial-lift selection, reducing downtime and lowering operating costs by nearly 50%. This paper describes interpretation results of a 4D seismic-monitoring program in a challenging Middle East carbonate reservoir.

This page pulls together technology-focused articles from various departments within JPT. This paper introduces a new core-analysis work flow for determining resistivity index (RI), formation factor (FF), and other petrophysical properties directly from an as-received (AR) set of core samples. In this paper, the authors discuss the characterization process for GR tools and how they behave in boreholes different from the one used in the University of Houston (UH) GR characterization pit. This paper discusses a study undertaken to gain better understanding of nuclear magnetic resonance (NMR) characteristics of volcanic reservoirs with different lithologies. Formation evaluation drew special attention at the 2019 International Petroleum Technology Conference Education Week in Beijing, 24–28 March 2019. The student team that worked on Integrated Formation Evaluation for Resources Exploration and Reservoir Delineation won the first-place award. The first subsea multiphase boosting system was installed in 1994.

Steam generation for the purposes of thermal recovery includes facilities to treat the water (produced water or fresh water), generate the steam, and transport it to the injection wells. A steamflood uses high-quality steam injected into an oil reservoir. The quality of steam is defined as the weight percent of steam in the vapor phase to the total weight of steam. The higher the steam quality, the more heat is carried by this steam. High-quality steam provides heat to reduce oil viscosity, which mobilizes and sweeps the crude to the producing wells.

The Light Oil Steam Flood (LOSF) is proposed to increase the recovery from Mauddud reservoir in Bahrain Field. Mauddud has been on gas injection since 1938, yet residual oil saturation is still high in the gas cap due to its oil wettability. Several core lab studies were conducted confirming the high oil saturation in the gas cap. Steam flood core lab experiments were conducted recently and confirmed the residual oil saturation could reach to less than 10%. The thermal pilot project in Mauddud has gone through the following stages:

The first pilot started in 2013 and operated for 2.5 years: It has one horizontal well in the gas cap, one vertical producer, four vertical injectors with three Temperature Observation Wells (TOWs) clustered around one of the injectors.

Throughout these stages, production monitoring, logging, core studies and simulation studies have been carried to understand the LOSF mechanisms to increase Mauddud recovery from the gas cap.

This paper presents the evolution of pilot design concepts and simulation of the thermal recovery in Mauddud. It also study and assess the well configurations and pilot operating strategies designed for the thermal pilots. A sector model was constructed and calibrated, then used to select a well concept for the LOSF pilots. Seventeen different pilot concepts were considered during the selection process. The well configuration and operating strategies were driven to observe a quicker steam response in the first pilot. A number of sensitivities were conducted to develop a better understanding of the effects of the various reservoir factors.

A comprehensive study was then carried out to recommend a phase development approach for full-scale field development and establish a methodology for a full-field LOSF forecast. Full Field compositional model was built in thermal reservoir simulator and was then successfully history matched with seven components equations of state (EOS). A phased development approach was then proposed for full-scale field development. The initial development will focus on the mid-dip areas with higher remaining oil saturations and a thicker oil column. After establishing production in the mid-dip flanks, development could proceed to the crestal areas, which have lower oil saturations and would likely result in higher steam/oil ratios (SORs).

Summary

The 1st Eocene is a multibillion-barrel heavy-oil carbonate reservoir in Wafra field in the Partitioned Zone (PZ) between the Kingdom of Saudi Arabia and Kuwait. A large-scale steamflood pilot has been successfully completed in the 1st Eocene reservoir. The large-scale pilot (LSP) was the first multipattern steamflood in a carbonate reservoir in the Middle East, and consisted of sixteen 2.5-acre inverted 5-spot patterns with associated steamflood and production facilities. The primary objective of the LSP was to identify and mitigate technical and economic risks and uncertainties in carbonate steamflooding to assist in the broader Wafra full-field steamflood development (FFSFD) decisions. The key technical uncertainties related to the steamflooding in the 1st Eocene reservoir were identified, categorized, and prioritized. These were then used as a basis to create surveillance and subsurface response plans. Success measures were developed to assess success in steamflooding this carbonate reservoir. These success measures were derived from the key metrics that were prerequisites for the FFSFD. The pilot met all the success measures, thereby mitigating the key technical uncertainties, and opened the path to FFSFD. This paper describes the elements of pilot planning and the results achieved during pilot execution. The emphasis, specifically, is on the achievements against the success measures set for the project; the insights into the pilot behavior from detailed analysis of production, pressure, and temperature data; and the progress made in identifying and mitigating key uncertainties in carbonate steamflooding.

Wafra is one of four major fields located in the PZ (Figure 1). Because of the low primary oil recovery and large original oil in place of the Wafra Eocene reservoirs, a significant EOR opportunity exists. A detailed geological description of the reservoir is provided in the complete paper. Because of key surface and subsurface uncertainties, along with the high cost of implementing a full-field steamflood-development (FFSFD) project, a phased, sequential approach, from piloting to FFSFD, was implemented. This approach was required so that critical uncertainties could be evaluated efficiently and sequentially in a timeframe consistent with overall reservoir-development objectives while managing capital exposure. This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 191695, “Results From a Phased Piloting Approach in the First Eocene Reservoir of Wafra: Reducing Uncertainties in Carbonate Steamflood Development,” by David Barge, SPE, Joel Brown, Raushan Kumar, Chris Lolley, SPE, Ruurd Bartlema, and Saleh Al-Ghamdi, Chevron, prepared for the 2018 SPE Annual Technical Conference and Exhibition, Dallas, 24–26 September. The paper has not been peer reviewed.