Erwyn Saputra

ANALISIS PRESSURE BUILD UP DAN PENENTUAN DELIVERABILITAS SERTA PREDIKSI PLATEAU TIME SUMUR GAS CR-7 PETROCHINA INTERNATIONAL JABUNG LTD

Introduction

Analisis pressure build up dan penentuan deliverabilitas serta prediksi plateau time sumur gas cr-7 petrochina international jabung ltd. Analisis pressure build-up & deliverabilitas sumur gas CR-7 Petrochina Jabung. Menentukan karakteristik reservoir (permeabilitas, skin, Pi), AOFP, GIIP, dan prediksi plateau time produksi.

Abstract

AbstrakPada pengujian Sumur Gas CR-7 dapat dilakukan antara lain uji pressure build Up test dan uji modified isochronal test. Karakteristik Reservoir yang dapat diperoleh dari analisis hasil uji sumur antara lain permeabilitas, skin dan tekanan reservoir (Pi). Selain itu didapatkan juga Absolute Open Flow Potential (AOFP) dari uji deliverabilitas sumur. Batuan formasi lapisan yang diuji merupakan batu pasir. Pada analisis hasil uji pressure build up menggunakan metode Type curve Pressure Derivative dan Horner Plot serta uji deliverabilitas modified isochronal test dengan metode C and n dan metode Laminar Inertia Turbulent, dengan bantuan perangkat lunak kemudian hasil tersebut dibandingkan dengan perhitungan pada Miscrosoft Excel, kemudian dari data yang diperoleh dapat diketahui beberapa parameter beserta karakteristik formasi yang dapat digunakan untuk menentukan besarnya GIIP (by well) seperti porositas, saturasi, faktor volume formasi gas, ketebalan dan luas area. Sedangkan dari hasil uji deliverabilitas dapat diperhitungkan inflow performance relationship (IPR) selanjutnya hasil analisis GIIP (by well), IPR dan VLP sumur akan digunakan untuk menentukan plateau time Sumur CR-7 pada berbagai laju alir produksi. Berdasarkan hasil analisis Pressure Derivative didapatkan karakteristik reservoir yaitu model reservoir adalah Two Layers dan model boundary adalah One Fault, serta didapat nilai initial pressure (Pi) sebesar 1802 psi. Pada reservoir memiliki nilai total skin yaitu -4,31, nilai permeabilitas sebesar 40,769 mD. Sedangkan pada hasil analisis Horner Plot didapatkan nilai slope -44.043, kemudian nilai radius investigasi diperoleh sebesar 905,529 ft. Selanjutnya melalui perhitungan volumetrik didapatkan besarnya GIIP (by well) sebesar 2556,171 mmscfd. Kemudian melakukan prediksi plateau time Sumur Gas CR-7 menggunakan Microsoft excel. Kata Kunci: Uji Pressure Build Up, Pressure Derivative dan Deliverability AbstractWell testing job that applied in this well are Pressure Build Up test, and Modified Isochronal Test. Characteristics of reservoir that can be obtained from the tests are permeability, formation damage factor (skin factor) and initial reservoir pressure. Also can be obtained Absolute Open Flow Potential from the well deliverability test. The well produces wet gas. The layer that being tested is a sandstone formation. The analysis of Pressure Build Up test uses Horner method, and Type Curve Pressure Derivative. The analysis of Modified Isochronal Test uses C and N method, and Laminar Inertia Turbulent method. Both analysis are done by perangkat lunak. Then, the results are compared by output from the calculation using Microsoft Excel, then Based on pressure build up result can be known several parameters of formation characteristics that can be used to determine GIIP (by well) example porosity thicknes, saturation etc. Meanwhile, deliverability result can be used to determineformation inflow performance relationship (IPR) and vertical lift performance (VLP) from the wellbore. Moreover, from GIIP (by well) analysis will calculate plateau time of VLL-1 well from various production flow rate. These two well test analysis will done by software and manual calculation as a comparison Based on pressure derivative analysis results, obtained reservoir characteristics which is two layers as the reservoir model, and boundary model is one fault, and also initial pressure (Pi) values at 1802 psi. reservoir obtained negative total skin value of -4,31, permeability of 40,769 mD,meanwhile, from radius of investigastion 905,529 ft. next, volumetric calculation obtained GIIP (by well) 2556,171 mmscfd. And then, plateau time predicted with Excel ManualKeywords: Pressure Transient , Pressure Derivative and Deliverability

Review

This paper presents a detailed analysis of the CR-7 gas well, focusing on reservoir characterization, deliverability assessment, and plateau time prediction. Utilizing both Pressure Build-Up (PBU) tests and Modified Isochronal Tests, the study aims to derive crucial reservoir parameters such as permeability, skin factor, and initial reservoir pressure (Pi). Furthermore, it seeks to determine the Absolute Open Flow Potential (AOFP) and estimate the Gas Initially In Place (GIIP) for the well. The ultimate objective is to integrate these findings with Inflow Performance Relationship (IPR) and Vertical Lift Performance (VLP) to predict the plateau time of the CR-7 well under various production scenarios, providing valuable insights for optimizing gas production and reservoir management. The methodology employed is robust, combining industry-standard analysis techniques for both PBU and deliverability tests. PBU analysis was conducted using Type Curve Pressure Derivative and Horner Plot methods, while deliverability was assessed via the C and n method and the Laminar Inertia Turbulent method. The authors leverage "perangkat lunak" (software) for these analyses, with results subsequently compared against calculations performed in Microsoft Excel. Key findings from the pressure derivative analysis indicate a reservoir model of Two Layers with a One Fault boundary, an initial pressure of 1802 psi, a favorable negative total skin of -4.31 (suggesting stimulation or natural enhancement), and a permeability of 40.769 mD. The Horner Plot yielded a slope of -44.043 and a radius of investigation of 905.529 ft. Volumetric calculations resulted in a GIIP (by well) of 2556.171 mmscfd, which then formed the basis for plateau time prediction using Excel. Overall, the study offers a comprehensive approach to gas well performance evaluation, providing critical data for the CR-7 well. The detailed reservoir characterization, including the identification of a two-layer, one-fault system and a negative skin factor, offers practical implications for future development strategies. However, the abstract could benefit from clarifying the specific "perangkat lunak" used and the degree of agreement found when comparing software results with manual Excel calculations. More importantly, the reported unit for GIIP "2556.171 mmscfd" is unconventional, as GIIP is typically a static volume (mmscf) rather than a daily rate; this requires clarification or correction. Despite this minor ambiguity, the paper's integrated analysis of well tests, deliverability, and production forecasting contributes significantly to understanding and managing the CR-7 gas well, making it a valuable resource for field engineers and reservoir managers.

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