In petroleum exploration, the geological model is developed and then proved, disproved, or modified by drilling. The subsequent commercial decisions are based on the existence and mobility of hydrocarbons within the pores of the reservoir rock under downhole conditions. When a hydrocarbon-bearing formation is cored, the properties of the fluid contained in the pores changes … What is petrophysics?

The evaluation requirements for drilling operations are identified by the Reservoir and Petroleum Engineering Department and are incorporated in the drilling programme for each well, or as a separate test programme. The implementation of the evaluation programme at the well site is generally carried out by the Logging Engineer under the supervision of the Drilling … Formation Evaluation – Organisation and Responsibilities

This article presents the following Formation Strength Tests Calculations: – Formation Intake Gradient (FIG) – Effective Mud Gradient (EMG) – Maximum Allowable Annular Surface Pressure (MAASP) Formation Intake Gradient (FIG) FIG (psi/ft) = LOP + (CSD x MG)                       (CSD – RKB) Effective Mud Gradient (EMG) EMG (psi/ft) = LOP + (CSD x … Formation Strength Tests Calculations

Formation strength tests (FST’s – sometimes referred to as “leak-off tests” (L.O.T) or “limit tests” or “formation intake tests” (F.I.T)) measure the formation strength below the casing. FST’s, shall be done below all casing shoes (or outside milled casing windows for side-tracks) in exploration and appraisal wells. For development wells, the FST will be done … Formation Strength Tests Profiles and Definitions

Limit or leak-off tests in development wells may be omitted if no hydrocarbon bearing and/or overpressured formations are to be penetrated. Information obtained from leak-off tests in straight holes is not applicable to deviated holes in the same field (and vice versa). Only measurements in the deviated hole themselves should be used. It is not … Formation strength testing

The evaluation requirements for a particular well depend upon the type of well being drilled eg., development, appraisal or exploration.  The detailed requirements for each well shall be indicated in the Well Proposal. 1. Evaluation Standards Evaluation Categories Typically, the formation evaluation carried out by the Drilling Department falls into two categories: Formation evaluation undertaken … Evaluation Standards

This article describes the responnsibilities for planing and safety, logging, Pipe conveyed logging(PCL), coring, mud logging, FST and Cement evaluation logging. Planning and Safety The Drilling Supervisor shall ensure: all personnel are familiar with the mandatory requirements for explosive and radioactive materials, (explosive magazines and radioactive stores shall be set aside in a designated, marked … Responsibilities for Evaluation Operations

This article presents Formation Strength Tests Equipment and Procedure. Equipment Requirements A formation strength test requires: a Cement Pump with mud tank calibrated in ¼ bbl calibrated gauges covering anticipated pressure range mounted on a dedicated manifold a chart recorder a recording form. Test Pressure Limitations The test pressure shall be limited to a maximum … FST Procedure

Evaluation work for an exploration well will be carried out from the Central Offices, so it is essential that the staff are kept up-to-date about what is happening in the field, and receive the data that they require, in the format they require. 1 General The Drilling manager should have a face-to-face meeting with Central … Well evaluation guidelines for exploration wells