Tight Oil Field Development Challenges, Lessons Learnt and Successful Implementation of Selected Artificial Lift (SRP) Along with Operational & Digital Solutions: ABH Field, Rajasthan, India

Abstract

Aishwariya Barmer Hill (ABH) field area consists of a laminated high porosity (25-35%), low permeability (~1 mD) unit of 50-250 meters thick hydrocarbon bearing payzone. With the success of the first 6 pilot wells, it was decided to extend to the whole field with more than 44 horizontal wells. The horizontal wells are ~2300-2600 mMD long, lateral average length of 1000m and multistage hydraulic fracturing (10-17). These wells face numerous complications due to high gas-oil ratio, sand production, and corrosion tendencies because of high CO2 mole percent concentration (40-60%) in fluid. Further complications include downhole pumps setting at very high deviation (60-65 deg), rod failures-wear in high deviation wells, rod rotation due to deviation and gradual productivity declines due to sand deposition at lower side of downhole completion. Due to low permeability and low mobility fluid nature, it was necessary to find efficient ways to enhance the overall hydrocarbon recovery factor of the field. Several sensitivities were performed, on the number of wells, number of hydraulic fractures, well design, artificial lift options, water, and gas injection. According to the sensitivities results, the best developed scenario envisages high number of multiple frac wells to increase the recovery factor. Based on the detailed evaluation of available artificial lift options, SRP was selected over Jet pumps as the most suitable artificial lift considering the requirement of large drawdowns & operating costs of lifts. The risk of gas issues was mitigated by keeping the tubing-production casing annulus vented and further alleviated by running suitable downhole gas separators. Other problems were analyzed, and multiple attempts of solution implementation were done. This paper addresses an inhouse ways to tackle sand, high gas rate issues, along with rectifications &learning of other problems faced during the last 3 years of field operations, including digitalization projects for visualization of well behavior. This paper also addresses a few remarkable calculated parameters which are - actual production loss calculations whenever well is shut-in (considering wellbore column storage effects), calculated gas free liquid level pump submergence and pump intake pressure from pump load live data. The purpose of this paper is to describe technical & operational challenges along with lessons learnt/solutions implemented in last 3 years.