Volumes and Risks Assessment for Conventional and Unconventional Plays and Prospects

Course Description

The course enables participants to transform qualitative geological descriptions of plays and prospects into technically robust quantitative success-case and risked volumetric models. Obtained learnings will help participants to evaluate probabilities of success (PoS) for exploration plays, segments, prospects, wells and portfolios and to assess the range of petroleum volumes in exploration projects. Examples and case studies come from both conventional and unconventional plays, prospects and wells around the world. The learning objectives are achieved through well-illustrated lectures, numerous hands-on exercises and active class discussions.

We will cover the following topics:

  • Play-based exploration;
  • Assessment of success-case volumes for plays (conventional and unconventional), segments, prospects, wells and portfolios;
  • Assessment of exploration risks and probabilities of success;
  • Biases and logical fallacies in;
  • Post-mortem analysis.

Course Objectives

Upon completion of the course, participants will be able to:

  • Use play-based exploration approach and tools (e.g., Common Risk Segment mapping, Field Size Distribution analysis, Creaming Curves etc.) to locate sweet spots in conventional and unconventional plays and assess remaining play/basin potential;
  • Calculate deterministic potential (success-case) petroleum resources in conventional prospects and in unconventional plays. Assess and justify the range and probabilistic distribution of input parameters used in volumetric calculations;
  • Assess geological risks and PoS for conventional and unconventional exploration, appraisal and development segments;
  • Use industry-standard software (GeoX, REP or both) and run Monte-Carlo simulations to estimate unrisked and risked probabilistic volumes for plays, segments, prospects and wells;
  • Recognize biases and logical fallacies common in exploration assessments and know how to correct them;
  • Aggregate segments into a prospect and use risk and volumes dependencies between segments to estimate PoS and volumes for the prospect. Calculate PoS for wells;
  • Aggregate prospects and wells into exploration portfolio. Predict the outcomes of portfolio drill-out;
  • Evaluate drilling results to establish main reason(s) for well failure.

Course Outline

Day 1. Big picture trends in petroleum exploration. Play-based exploration. Fundamentals of volumetric and risk assessment for prospective segments.

The first day introduces the participants to global exploration trends and the concepts of Exploration Triangle and Play Based Exploration. You will learn the fundamentals of volumetric and risk assessment, the main definitions and the commonly used assessment tools (software).

  • Welcome and introductions;
  • Global trends in petroleum exploration since 1900;
  • Play-based exploration;
  • Common Risk Segment (CRS) maps;
  • Field size distributions;
  • Creaming curves;
  • Yet-to-Find resources;
  • Risk versus uncertainty;
  • Deterministic and probabilistic volumes;
  • Success-case and risked volumes;
  • Software tools used in the assessment of prospective resources.

Day 1 exercises:

  • Evaluate the play fairway, make CRS maps, locate sweet spots in the play;
  • Build and evaluate field size distributions and creaming curves, define remaining play/basin potential.

Day 2. Basics of statistics, distributions and probabilities. Biases and fallacies in exploration. Volumetrics and risking for a segment of conventional petroleum resources.

The second day starts with the discussion of statistical parameters, distributions and probabilities. Participants will use real-world data (area, thickness, Net/Gross, porosity, saturation, Formation Volume Factor, Recovery Factor) to build distributions as inputs into volumetric models. This will be followed by the discussion of biases and fallacies in petroleum assessments and the tools that help reduce them. We will finish the day by doing hands-on assessment of volumes and risk for a conventional prospect.

  • Meaning of basic statistical parameters (Mean, Mode, P10 etc.);
  • Distributions appropriate to use in petroleum exploration projects;
  • Where and how to get data to build distributions;
  • Main biases and logical fallacies common in petroleum exploration;
  • Techniques to reduce biases (Risk Tables, assurance teams);
  • Assessment of volumes and geological PoS for a segment;
  • Using information on Direct Hydrocarbon Indicators (DHIs) to update geological PoS;
  • Assessment of geological risks for appraisal and development wells.

Day 2 exercises:

  • Build porosity distribution for a segment;
  • Calculate volumes and evaluate sensitivities to various inputs for a conventional oil segment;
  • Assess success-case volumes, geological PoS and risked volumes for a conventional oil segment (real prospect from offshore West Africa).

Day 3. Volumetrics and risking for unconventional plays. Aggregation of segments into prospect. Portfolio analysis. Post-drilling analysis. The third day will start with the discussion of volumes and risk assessments for unconventional oil and gas plays (tight, shale, CBM). After that, we will discuss aggregation of segments into prospects and prospects into a portfolio. We will finish the course by studying how to do post-mortem analysis, learn from exploration successes and failures and become better explorers.

  • Assessment of volumes and risks for unconventional plays;
  • Aggregation of segments into prospect, with risk and volume dependencies;
  • Calculation of PoS for prospects and wells;
  • Aggregation of prospects into portfolio;
  • Learnings from discovery wells;
  • Learnings from dry holes;
  • Full Cycle Economics evaluation.

Day 3 exercises:

  • Assess in-place and recoverable volumes in unconventional shale gas and shale oil plays (real plays onshore Australia);
  • Assess recoverable volumes for small(ish) acreage of unconventional tight oil in the USA (real play in the Powder River basin);
  • Aggregate segments into a prospect, calculate values of PoS for the prospect and for the well;
  • Evaluate a dry hole, determine the reason for well failure.

Participants’ Profile

The course is designed for geoscientists, engineers and managers who work on exploration projects and require competency in the assessment of risks and volumes.

About the Instructor

Alexei V. Milkov is Full Professor and Director of Potential Gas Agency at Colorado School of Mines and a consultant to oil and gas industry. After receiving PhD from Texas A&M University, Dr. Milkov worked for BP, Sasol and Murphy Oil as geoscientist and senior manager. He explored for conventional and unconventional oil and gas in over 30 basins on six continents and participated in the discovery of more than 4 Billion BOE of petroleum resources. He also worked on several appraisal and production projects. Dr. Milkov has deep expertise in oil and gas geochemistry, petroleum systems modeling, exploration risk analysis, resource assessments and portfolio management. He published 50 peer-reviewed articles. Dr. Milkov received several industry awards including J.C. “Cam” Sproule Memorial Award from the American Association of Petroleum Geologists (AAPG) for the best contribution to petroleum geology and Pieter Schenck Award from the European Association of Organic Geochemists (EAOG) for a major contribution to organic geochemistry.